The Scribblings of Samuel Baughn: 2025

Hyaenodonts in GURPS

A very successful and diverse order of predators, Hyaenodonts resembled modern carnivores like wolves and lions, but weren’t closely related to them. They were Creodonts, a now extinct clade of meat-eaters. They were generally more carnivorous than even the carnivore clade, with teeth unsuited for anything except flesh. Most of them were had sturdy builds, short legs, and long heads.

They thrived in the warm climate of the Oligocene, then died off as global temperatures fell and landscapes shifted from dense woodland to open plains during the Miocene.

Apterodon

A small, semi-aquatic genus which used its strong jaws to crack shellfish open. Powerful front limbs allowed it to dig burrows for shelter.

ST 6; DX 12; IQ 3; HT 11.

HP 6; Will 11; Per 11; FP 11; Speed 6.00; Dodge 9; Move 8.

SM −1, 25 lbs.

Bite (14): 1d−2 cutting.

Traits: Amphibious; Bad Sight (Low Resolution); Born Biter 2; Breath Holding 5; Discriminatory Smell; Enhanced Move 1 (Ground Speed 16; Costs Fatigue, 1 FP/second); Night Vision 3; Striking ST 3 (Bite only); Quadruped; Ultrahearing; Wild Animal.

Skills: Brawling-14; Survival (Island/Beach)-13; Swimming-15.

Hyainalouros

A very big animal, possibly the largest hyper-carnivorous mammal ever. Despite its size, it was well suited for running. Megistotherium may be a close relative or even the same genus. Either way, it attained similar sizes, as did Simbakubwa.

ST 21; DX 10; IQ 3; HT 11.

HP 21; Will 12; Per 11; FP 11; Speed 5.00; Dodge 8; Move 5.

SM +2 (3 hexes), 1,100 lbs.

Bite (12): 3d+1 cutting.

Claw (12): 2d+1 cutting.

Traits: Bad Sight (Low Resolution); Born Biter 2; Discriminatory Smell; DR 3; Enhanced Move 2 (Ground Speed 20; Costs Fatigue, 1 FP/second); Night Vision 3; Striking ST 6 (Bite only); Parabolic Hearing 2; Quadruped; Ultrahearing; Wild Animal.

Skills: Brawling-12; Survival (Woodland)-12.

This profile represents a compromise between several wildly different size estimates for these animals. The smallest estimate would instead weigh around 600 lbs. and have ST and HP 17 (damage 2d+2 with a bite, 1d+2 with a claw), SM +1, Born Biter 3, and DR 2. The largest would be 3,300 lbs. and have ST and HP 30 (damage 4d+2 with a bite, 3d+2 with a claw), SM +3, Born Biter 1, and DR 4.

Hyaenodon

These dog-like creatures came in a huge variety of species, ranging from terrier to bear sized. All of them had large heads with long, powerful jaws. They seem to have used a combination of stalking, pouncing, and pursuit to capture prey, like lions. Sturdy teeth suggest they would bite and then hang on to struggling prey, also reminiscent of lions. Dissopsalis was a later genus with similar anatomy which survived into the late Miocene. Pyrocyon was another dog-shaped animal, a little smaller than the smallest Hyaenodon species. It lived in the early Eocene and, like a dog, was able to eat a wider variety of food than most of its relatives.

ST 9; DX 11; IQ 3; HT 11.

HP 9; Will 12; Per 11; FP 11; Speed 6.00; Dodge 9; Move 8.

SM 0, 80-90 lbs.

Bite (13): 1d cutting.

Claw (13): 1d−2 cutting.

Traits: Bad Sight (Low Resolution); Born Biter 3; Discriminatory Smell; DR 1; Enhanced Move 1 (Ground Speed 16; Costs Fatigue, 1 FP/second); Night Vision 3; Striking ST 4 (Bite only); Parabolic Hearing 2; Quadruped; Ultrahearing; Wild Animal.

Skills: Brawling-13; Climbing-12; Survival (Woodland)-14.

This profile suits mid-sized species such as H. horridus or H. leptorynchus or Dissopsalis. For a small species such as H. crucians (40 lbs.) reduce ST and HP to 7 and Striking ST to 3 (bite damage 1d−1, claw damage 1d−3). For the smallest, such as H. microdon and H. mustelinus (11 lbs.) or Pyrocyon (6 lbs.), reduce ST and HP to 4 and Striking ST to 2 (bite damage 1d−4, claw damage 1d−5) and remove DR. For the giant species like H. gigas, H. mongoliensis, and H. weilini (800-900 lbs.) raise ST and HP to 19, DR to 2 and Striking ST to 6 (bite damage 2d+3, claw damage 2d).

Kerberos

A large early Hyaenodont from Eocene Europe. It was a jaguar-sized ambush predator, poorly suited to running. It shared its habitat with the far smaller but generally similar Lesmesodon, which resembled a cross between a fox and a weasel. Exceptionally well-preserved remains show that it had long brown fur and a bushy tail. Galecyon was another small animal with a combination of canine and mustelid features from the same place and time, which spent more time on the ground.

ST 13; DX 11; IQ 3; HT 11.

HP 13; Will 11; Per 11; FP 11; Speed 6.00; Dodge 9; Move 6.

SM 0, 300 lbs.

Bite (13): 1d cutting.

Claw (13): 1d−2 cutting.

Traits: Bad Sight (Low Resolution); Born Biter 3; Discriminatory Smell; DR 1; Enhanced Move 1 (Ground Speed 12; Costs Fatigue, 1 FP/second); Night Vision 3; Striking ST 5 (Bite only); Parabolic Hearing 2; Quadruped; Temperature Tolerance (Heat) 2; Ultrahearing; Wild Animal.

Skills: Brawling-13; Climbing-12; Survival (Jungle)-12.

For Lesmesodon (1 lb.) reduce ST and HP to 2, SM to −4, Striking ST to 1 (damage 1d−5 with a bite, 1d−6 with a claw), and remove DR. For Galecyon (15 lbs.) reduce ST and HP to 5, SM to −2, Striking ST to 2 (damage 1d−3 with a bite, 1d−4 with a claw), increase Enhanced Move to 1.5 (Ground Speed 18), and remove DR and Climbing skill.

Dimetrodon in GURPS

Dimetrodon and Edaphosaurus (back) by Charles R. Knight (1897)

Dimetrodon is the most famous early synapsid. Indeed it is likely the only one which most people would recognize. Despite appearing alongside dinosaurs in works of fiction and cheap plastic toys, it died out millions of years before they evolved. Although sometimes called ‘mammal-like reptiles’, Dimetrodon and its relatives aren’t actually reptiles either. It did look reptilian, however, with scaly skin, sprawling legs, a thick tail, and a spectacular sail running along its spine.

The sail's purpose remains hotly debated. The leading theory suggests it regulated body temperature, capturing morning sunlight and managing heat throughout the day. Other hypotheses propose it served for sexual display, rival intimidation, or spinal stabilization during rapid movement. The apparently conspicuous sail might have actually provided camouflage by mimicking the silhouettes of plants or harmless herbivores. Rather than the commonly depicted thin membrane, the sail could have been a fleshy hump storing fat and fluids for lean periods. More outlandish theories include it functioning as a sensory organ for detecting wind and air vibrations, or even acting as an actual sail when swimming!

As one of its era's biggest land animals, Dimetrodon was an apex predator. Later species grew even larger with proportionally bigger sails. Though favoring wetland habitats, these adaptable beasts could survive in arid environments as well.

Dimetrodon

ST 16; DX 11; IQ 2; HT 13.

HP 16; Will 12; Per 10; FP 13; Speed 5.00; Dodge 8; Move 4.

SM +2 (4 hexes), 500 lbs.

Bite (13): 1d+1 cutting.

Traits: Bad Sight (Low Resolution); Born Biter 2; Cold-Blooded (50°); Discriminatory Smell; DR 2; Enhanced Move 1 (Ground Speed 8; Costs Fatigue, 1 FP/second); Quadruped; Wild Animal.

Skills: Brawling-14; Survival (Swampland)-14; Swimming-13.

This profile suits the later and larger species such as D. angelensis or D. grandis. Earlier species such as D. natalis (60 lbs.) could have ST and HP as low as 8 (bite damage 1d−3) and DR 1.

Metailurini in GURPS

The ‘dagger-toothed cats’ never got as large as the biggest saber-toothed cats. They had robust, conical, and relatively short fangs, well suited to throttling struggling prey. Their tails were almost as long as those of modern cats.

Dinofelis

This bulky ambush predator had powerful forelegs, which helped both in climbing and subduing prey.

ST 14; DX 13; IQ 4; HT 11.

HP 14; Will 10; Per 12; FP 11; Speed 6.00; Dodge 10; Move 7.

SM 0, 330 lbs.

Bite (15): 1d impaling.

Claw (15): 1d cutting.

Traits: Bad Sight (Low Resolution); Born Biter 1; Combat Reflexes; Discriminatory Smell; DR 1; Enhanced Move 1 (Ground Speed 14; Costs Fatigue, 1 FP/second); Limited Camouflage; Night Vision 3; Parabolic Hearing 1; Quadruped; Silence 1; Ultrahearing; Vibration Sense (Air; Short Range 1); Wild Animal.

Skills: Brawling-14; Climbing-16; Stealth-13; Survival (Woodlands)-13.

Metailurus

This cat’s long, powerful legs allowed it to make impressive leaps, ideal for pouncing from ambush.

ST 10; DX 13; IQ 4; HT 11.

HP 10; Will 10; Per 12; FP 11; Speed 6.00; Dodge 10; Move 12.

SM 0, 110 lbs.

Bite (15): 1d−2 impaling.

Claw (15): 1d−2 cutting.

Traits: Bad Sight (Low Resolution); Born Biter 1; Combat Reflexes; Discriminatory Smell; Limited Camouflage; Night Vision 3; Parabolic Hearing 1; Quadruped; Silence 1; Ultrahearing; Vibration Sense (Air; Short Range 1); Wild Animal.

Skills: Brawling-14; Climbing-15; Jumping-16; Stealth-14; Survival (Woodlands)-12.

Yoshi

A cheetah-like animal with a slender build, long-legs, and short muzzle.

ST 9; DX 13; IQ 4; HT 11.

HP 9; Will 10; Per 12; FP 11; Speed 6.00; Dodge 10; Move 13.

SM −1, 85 lbs.

Bite (15): 1d−2 impaling.

Claw (15): 1d−2 cutting.

Traits: Born Biter 1; Combat Reflexes; Discriminatory Smell; Enhanced Move 1 (Ground Speed 26; Costs Fatigue, 1 FP/second); Limited Camouflage; Night Vision 1; Parabolic Hearing 1; Quadruped; Silence 1; Ultrahearing; Vibration Sense (Air; Short Range 1); Wild Animal.

Skills: Brawling-15; Running-16; Stealth-14; Survival (Plains)-12.

Homotherini in GURPS

The ‘scimitar cats’ had lighter builds and were better adapted for running than their relatives the Smilodontini. It is believed that their flattened and serrated fangs would have been fully covered by lips. Their overall appearance would have been similar to modern cats, mostly distinguished by their short tails.

Amphimachairodus

A huge cat, even larger than Smilodon populator, with relatively short legs, necessitating ambush as its main hunting strategy. Sexual dimorphism in size suggests that it was a social animal. It seems to have preferred smaller prey. Its close relative Nimravides was better built for speed and preferred big game. It seems to have used its jaws in a manner similar to modern big cats, clamping onto the throat to strangle large prey. The largest species, N. catocopis, was similar in size to Amphimachairodus, but others were less than one-third their weight.

ST 19; DX 12; IQ 4; HT 12.

HP 19; Will 10; Per 12; FP 12; Speed 6.00; Dodge 10; Move 9.

SM +1 (2 hexes), 900 lbs.

Bite (14): 2d impaling.
Claw (14): 2d cutting.

Traits: Bad Sight (Low Resolution); Born Biter 1; Chummy; Combat Reflexes; Discriminatory Smell; DR 1; Enhanced Move 1 (Ground Speed 18; Costs Fatigue, 1 FP/second); Limited Camouflage; Night Vision 3; Parabolic Hearing 1; Quadruped; Silence 1; Ultrahearing; Vibration Sense (Air; Short Range 1); Wild Animal.

Skills: Brawling-14; Stealth-14; Survival (Plains)-14.

For Nimravides catocopis, increase Move to 10, (Ground Speed 20 with Enhanced Move), and remove Chummy. Smaller species such as N. galiani (260 lbs.) and N. thinobates (300 lbs.) also reduce ST and HP to 13 (bite and claw damage 1d) and SM to 0.

Homotherium

A relatively slender, long-legged cat, well suited to high-speed chases across open ground. Well-preserved remains show that it had a plain brown coat as an infant. It seems to have hunted very large prey, which indicates it probably hunted in groups. Its relative Lokotunjailurus was even more lightly built. Both had enlarged dewclaws to assist in grappling prey.

ST 15; DX 13; IQ 4; HT 11.

HP 15; Will 10; Per 12; FP 11; Speed 6.00; Dodge 10; Move 10.

SM +1 (2 hexes), 440 lbs.

Bite (15): 1d+1 impaling.
Claw (15): 1d+1 cutting.

Traits: Born Biter 1; Chummy; Combat Reflexes; Discriminatory Smell; DR 1; Enhanced Move 1 (Ground Speed 20); Night Vision 1; Parabolic Hearing 1; Quadruped; Silence 1; Ultrahearing; Vibration Sense (Air; Short Range 1); Wild Animal.

Skills: Brawling-15; Running-13; Stealth-12; Survival (Plains)-12; Wrestling-15.

For Lokotunjailurus, reduce ST and HP to 12 (bite and claw damage 1d−1), SM to 0, increase Move to 12 (Ground Speed 24 with Enhanced Move), and remove Chummy.

Xenosmilus

The ‘cookie-cutter cat’ not only had two large slicing fangs, but also serrated incisors. It is believed to have used these to carve chunks out of its victims, killing them slowly from blood loss. It was a bulky animal, almost bear-like in its proportions.

ST 18; DX 11; IQ 4; HT 12.

HP 18; Will 10; Per 12; FP 12; Speed 6.00; Dodge 10; Move 8.

SM +1 (2 hexes), 770 lbs.

Bite or Claw (13): 2d cutting.

Traits: Bad Sight (Low Resolution); Born Biter 1; Combat Reflexes; Discriminatory Smell; DR 1; Enhanced Move 1 (Ground Speed 16; Costs Fatigue, 1 FP/second); Limited Camouflage; Night Vision 3; Parabolic Hearing 1; Quadruped; Silence 1; Ultrahearing; Vibration Sense (Air; Short Range 1); Wild Animal.

Skills: Brawling-13; Climbing-13; Stealth-14; Survival (Woodlands)-12.

Smilodontini in GURPS

Promegantereon was the earliest known member of the ‘dirk-toothed cats’. It was leopard-sized and well suited to climbing. Although it had long upper canines and reduced incisors, these features weren’t nearly as pronounced as they would become in later genera. Its descendant Paramachaerodus had somewhat more powerful shoulders, indicating a preference for grappling with claws before using its teeth. Rhizosmilodon was a larger and more robust animal, but still lacked truly massive fangs. Megantereon was even bigger and did have long fangs, but was still smaller and less well armed than Smilodon fatalis. It also had a distinctive flange under its chin, a feature which convergently evolved in many other saber-toothed predators.

Promegantereon

ST 10; DX 13; IQ 4; HT 11.

HP 10; Will 10; Per 12; FP 11; Speed 6.00; Dodge 10; Move 10.

SM 0, 140 lbs.

Bite or Claw (15): 1d−2 cutting.

Traits: Bad Sight (Low Resolution); Born Biter 2; Catfall; Combat Reflexes; Discriminatory Smell; DR 1; Enhanced Move 1 (Ground Speed 20; Costs Fatigue, 1 FP/second); Flexibility; Limited Camouflage; Night Vision 3; Parabolic Hearing 1; Quadruped; Silence 1; Ultrahearing; Vibration Sense (Air; Short Range 1); Wild Animal.

Skills: Brawling-15; Climbing-16; Stealth-14; Survival (Woodlands)-12.

For Paramachaerodus, add Wrestling-14.

Rhizosmilodon

ST 11; DX 12; IQ 4; HT 12.

HP 11; Will 10; Per 12; FP 12; Speed 6.00; Dodge 10; Move 10.

SM 0, 170 lbs.

Bite or Claw (14): 1d−1 cutting.

Skills: Brawling-14; Climbing-14; Stealth-14; Survival (Woodlands)-12; Wrestling-14.

Techniques: Targeted Attack (Brawling Bite/Neck)-12.

Megantereon

ST 12; DX 12; IQ 4; HT 12.

HP 12; Will 10; Per 12; FP 12; Speed 6.00; Dodge 10; Move 10.

SM 0, 220 lbs.

Bite (14): 1d−1 impaling.

Claw (14): 1d−1 cutting.

Skills: Brawling-14; Stealth-14; Survival (Woodlands)-12; Wrestling-14.

Techniques: Targeted Attack (Brawling Bite/Neck)-12.

Ground Sloths in GURPS

Ground sloths are an example of a body-plan which has evolved several times in mammals; large semi-upright herbivores with formidable claws on their forelimbs. They were ancestral to modern sloths, but were very different in appearance and habits.

They usually walked on all fours, resting their weight on the knuckles of their ‘hands’ and the outer edges of their back feet. These feet were very strange, with the inner toes being rotated away from the ground so that their claws turned inwards. At the back of each foot was a bony extension, resembling an additional toe. Despite this curious anatomy and the great size of some of the sloths, it seems they were able to rear up on their hind limbs, using their thick tails as a third point of support. This allowed them to reach up into tall trees to bring buds, leaves, and fruit close enough to seize with their prehensile lips. It seems likely that they also used their claws for defense and competition with each other for mates.

Their metabolisms appear to have been fairly slow, a feature they share with modern sloths. Combined with their bulk and thick coats of fur offering significant insulation, they would have been able to survive on a relatively meager diet.

Megalonychids

Megalonyx (‘Great Claw’) remains were first discovered in West Virginia and named by Thomas Jefferson, who published a paper on them. Jefferson assumed that the claws must have come from a giant predator, only later learning of the existence of Megatherium and concluding that the two creatures must be related. It was a fairly typical ground sloth, distinguished mostly by the fact it lived in the pine woods of North America. Its ancestor Pliometanastes was only slightly smaller and crossed into North America before it had fully joined to South America by island-hopping. Their South-American relative, Ahytherium was only about two-thirds their weight.

Megalonyx

ST 25; DX 9; IQ 2; HT 12.

HP 25; Will 10; Per 10; FP 12; Speed 4.00; Dodge 7; Move 4.

SM +2 (3 hexes), 2,000 lbs.

Claw (11): 2d+3 cutting.

Traits: Bad Sight (Low Resolution); Discriminatory Smell; DR 3; Night Vision 1; Reduced Consumption 2 (Food Only); Semi-Upright; Temperature Tolerance (Cold) 3; Wild Animal.

Skills: Brawling-11; Survival (Woodlands)-10.

Use the same profile for Pliometanastes. For Ahytherium (1,300 lbs.) reduce ST and HP to 22 (claw damage 2d+1).

Megatherids

Megatherium was one of the largest ground sloths, around the size of an Asian elephant. It had an even more robust skeleton and proportionally longer claws that its relatives. Its relative Eremotherium was even larger and lived in warmer regions, so it may have had little or no fur.

Megatherium

ST 41; DX 8; IQ 2; HT 13.

HP 41; Will 10; Per 10; FP 13; Speed 4.00; Dodge 7; Move 5.

SM +3 (10 hexes), 8,500 lbs.

Claw (10): 4d+5 cutting or impaling.

Traits: Bad Sight (Low Resolution); Discriminatory Smell; DR 4; Night Vision 1; Reduced Consumption 2 (Food Only); Semi-Upright; Temperature Tolerance (Cold) 2; Wild Animal.

Skills: Brawling-10; Survival (Woodlands)-10.

For Eremotherium (10,000 lbs.) increase ST and HP to 43 (claw damage 5d+3) and remove Temperature Tolerance.

Mylodontids

Some members of this family had numerous small bony plates embedded in their skin, making them very challenging prey even for fearsome predators such as Smilodon populator. Mylodon lived in the Southern end of South America and was around the size of a modern rhinoceros. Although it mostly ate grasses, there is evidence that it also enjoyed meat from time to time, probably scavenged carrion or the remains of unfortunate predators which misjudged the sloth. Its close relative Paramylodon lived in North America, and was very similar. Lestodon lived slightly further North of Mylodon and grew to the size of an elephant. Glossotherium was smaller, and avoided predators and inclement weather by digging immense burrows. Catonyx was a distant relative which grew to about the same size as Mylodon, while Scelidotherium and Thinobadistes were only about half its weight.

Mylodon

ST 31; DX 9; IQ 2; HT 12.

HP 31; Will 10; Per 10; FP 12; Speed 4.00; Dodge 7; Move 4.

SM +3 (8 hexes), 3,600 lbs.

Claw (11): 3d+6 crushing.

Traits: Bad Sight (Low Resolution); Discriminatory Smell; DR 5; Night Vision 1; Reduced Consumption 2 (Food Only); Semi-Upright; Temperature Tolerance (Cold) 2; Wild Animal.

Skills: Brawling-11; Survival (Plains)-10.

Use the same profile for Paramylodon. For Lestodon (9,000 lbs.) increase ST and HP to 42 (claw damage 4d+9), and DR to 6. For Glossotherium (2,800 lbs.), reduce ST and HP to 28 (claw damage 3d+4), SM to +2, DR to 4. For Catonyx, reduce DR to 3 and Temperature Tolerance to 1. For Scelidotherium (1,900 lbs) or Thinobadistes (2,000 lbs.) reduce ST and HP to 25 (claw damage 2d+5), SM to +1, DR to 2, and Temperature Tolerance to 1.

Nothrotherids

Although not as impressive as the truly giant sloths, these bear-size animals still had thick hide and fearsome claws. Nothrotherium lived in dry, open forests and may have been able to climb trees, while Nothrotheriops was slightly larger and lived in arid scrubland.

Nothrotherium

ST 14; DX 10; IQ 2; HT 12.

HP 14; Will 10; Per 10; FP 12; Speed 4.00; Dodge 7; Move 4.

SM +1 (3 hexes), 330 lbs.

Claw (12): 1d cutting.

Traits: Bad Sight (Low Resolution); Discriminatory Smell; DR 2; Night Vision 1; Reduced Consumption 2; Semi-Upright; Wild Animal.

Skills: Brawling-12; Climbing-12; Survival (Woodlands)-10.

For Nothrotheriops (550 lbs.) increase ST and HP to 16, remove Climbing skill and replace Survival (Woodlands) with Survival (Desert)-13.

Hemicyon in GURPS

Although the ‘dog-bear’ was more closely related to modern bears than dogs, it was extremely dog-like in appearance (although more robust and with a larger head than modern canines of its size). Its diet was highly carnivorous and it was probably a pursuit predator.

Hemicyon

ST 10; DX 12; IQ 4; HT 12.

HP 10; Will 12; Per 12; FP 12; Speed 6.00; Dodge 9; Move 9.

SM 0 (2 hexes), 110-140 lbs.

Bite (14): 1d-3 cutting.

Traits: Bad Sight (Low Resolution); Born Biter 2; Discriminatory Smell; DR 1; Enhanced Move 1 (Ground Speed 18); Night Vision 1; Parabolic Hearing 1; Quadruped; Ultrahearing; Wild Animal.

Skills: Brawling-14; Stealth-12; Survival (Plains)-14.

Amphicyonids in GURPS

The 'bear-dogs' included the ancestors of both bears and dogs. The earliest examples were small, low-slung animals which vaguely resembled civets or mongooses. They were likely tree-dwelling omnivores. The earliest known is the North-American Gustafsonia cognita. Slightly later examples with essentially similar body-plans and lifestyles include the Eurasian Cynodictis lacustris and the North-American Daphoenus hartshornianus. Larger relatives of the latter include the coyote-sized D. vetus and D. ruber.

Early amphicyonid

ST 5; DX 12; IQ 3; HT 11.

HP 5; Will 11; Per 12; FP 11; Speed 6.00; Dodge 9; Move 9.

SM −2, 12-20 lbs.

Bite (14): 1d-5 cutting.

Traits: Bad Sight (Low Resolution); Born Biter 2; Discriminatory Smell; Limited Camouflage; Night Vision 3; Parabolic Hearing 1; Quadruped; Ultrahearing; Wild Animal.

Skills: Brawling-14; Climbing-14; Stealth-14; Survival (Woodlands)-14.

Larger species (25-30 lbs.) would have ST and HP 6, SM −1.

Later species tended to be larger, more carnivorous, and more adapted to life on the ground. Daphoenodon were wolf-like pursuit predators. They appear to have been eventually out-competed in this niche by canines, who were even better adapted to running.

Daphoenodon superbus by R. B. Horsfall (1913)

Daphoenodon

ST 11; DX 12; IQ 3; HT 12.

HP 11; Will 12; Per 12; FP 12; Speed 6.00; Dodge 9; Move 8.

SM 0, 150-190 lbs.

Bite (14): 1d-2 cutting.

Traits: Bad Sight (Low Resolution); Born Biter 2; Discriminatory Smell; DR 1; Enhanced Move 1 (Ground Speed 16); Limited Camouflage; Night Vision 2; Parabolic Hearing 1; Quadruped; Ultrahearing; Wild Animal.

Skills: Brawling-14; Stealth-14; Survival (Plains)-14.

Ysengrinia was a genus of pure carnivores, although their relatively short legs suggest they may have had to rely on ambush and scavenging rather than long-distance pursuits. The overall appearance seems to have been that of a very robust big cat with a dog-like head. European species such as Y. gerandiana, Y. tolosana, and Y. valentiana were the size of large jaguars, while the North-American Y. americana was a massive creature the size or a lion.

Magericyon was a later European genus which had a similar size to Y. americana and competed with saber-toothed cats for the role of apex predator. Magericyon was closely related to the diverse and wide-spread genus Amphicyon, the smallest of which (A. astrei) was similar to the European species of Ysengrinia, while larger ones were the size of a tiger (in the case of A. gutmani), polar bear (A. frendens), or kodiak bear (A. ingens). Ischyrocyon was another genus which achieved sizes similar to A. frendens.

Amphicyon attacking Miolabis by Roger Witter (2018)

Amphicyon astrei

ST 12; DX 12; IQ 3; HT 12.

HP 11; Will 12; Per 12; FP 12; Speed 6.00; Dodge 9; Move 5.

SM +1 (2 hexes), 200-240 lbs.

Bite (14): 1d-2 cutting.

Traits: Bad Sight (Low Resolution); Born Biter 2; Discriminatory Smell; DR 1; Enhanced Move 2 (Ground Speed 20; Costs Fatigue, 1 FP/second); Limited Camouflage; Night Vision 2; Parabolic Hearing 1; Quadruped; Ultrahearing; Wild Animal.

Use the same profile for European Ysengrinia species. For Y. americana, Magericyon, or mid-sized species of Amphicyon (400-450 lbs.) increase ST and HP to 15, which changes bite damage to 1d. A. gutmani (550 lbs.) increases ST and HP to 16 (bite damage 1d). For A. frendens or Ischyrocyon (950 lbs.) increase ST and HP to 20 (bite damage 2d−2) and DR to 2. For A. ingens (1,200 lbs.) increase ST and HP to 21 (bite damage 2d−1) and DR to 2.

Smilodon in GURPS

The creature that stood in the gate was like the embodiment of nightmare legend. Its color was of a curious pale quality which made it seem ghostly and unreal in the dim light. But there was nothing unreal about the low-hung savage head, and the great curved fangs that glistened in the firelight. On noiseless padded feet it approached like a phantom out of the past. It was a survival of an older, grimmer age, the ogre of many an ancient legend—a saber-tooth tiger. No Hyborian hunter had looked upon one of those primordial brutes for centuries. Immemorial myths lent the creatures a supernatural quality, induced by their ghostly color and their fiendish ferocity.

The beast that glided toward the men on the stakes was longer and heavier than a common, striped tiger, almost as bulky as a bear. Its shoulders and forelegs were so massive and mightily muscled as to give it a curiously top-heavy look, though its hind-quarters were more powerful than that of a lion. Its jaws were massive, but its head was brutishly shaped. Its brain capacity was small. It had room for no instincts except those of destruction. It was a freak of carnivorous development, evolution run amuck in a horror of fangs and talons.

Robert E. Howard, Beyond the Black River

Paleontologist P. W. Lund originally named Smilodon (‘double-edged-knife-tooth’) after the shape of its incisors, being unaware of the huge canine fangs of the upper jaw. These fangs are the most iconic feature of the cat, and have a flattened knife-like profile for slicing into flesh. It is believed that they were not used during the initial attack, but instead delivered the killing blow after the prey was immobilized with claws. The force of their bite was considerably less than that of a lion or tiger, but precision and deep penetration apparently allowed them to dispatch their victims quickly.

Aside from the teeth, they were distinguished from other cats by a heavy build, large size, short tail, and relatively massive front limbs. They seem to have been specialized in taking large prey from ambush, lacking the speed and endurance for pursuits over long distance. Fur length, coloration, and pattern are unknown, but some degree of camouflage seems likely. Although it isn’t clear what they sounded like, the bones related to vocalization don’t seem especially similar to those of any of their modern relatives, but are a bit closer to the big cats. They couldn’t purr, but may have been able to roar. Sexual dimorphism in skull shape, healed injuries, and several finds of multiple individuals suggest that they were at least somewhat social and may have hunted in packs.

Three species are known. The earliest and smallest was the North S. gracilis, which seems to have been a bit more of a generalist predator rather than a big-game specialist. S. fatalis was larger and more specialized. After spreading into South America it evolved into the even larger S. populator.

Smilodon populator by Charles R. Knight (1903)
Smilodon gracilis

ST 11; DX 12; IQ 4; HT 12.

Will 11; Per 12; Speed 6.00; Dodge 10; Move 10.

SM 0, 180 lbs.

Traits: Bad Sight (Low Resolution); Born Biter 1; Combat Reflexes; Discriminatory Smell; DR 1; Enhanced Move 1 (Ground Speed 20; Costs Fatigue, 1 FP/second); Limited Camouflage; Night Vision 3; Parabolic Hearing 1; Quadruped; Silence 1; Ultrahearing; Vibration Sense (Air; Short Range 1); Wild Animal.

Skills: Brawling-14; Stealth-14; Survival (Plains)-14; Wrestling-14.

Techniques: Targeted Attack (Brawling Bite/Neck)-12.

Smilodon fatalis

ST 16; DX 11; IQ 4; HT 13.

Will 11; Per 12; Speed 6.00; Dodge 10; Move 9.

SM +1 (2 hexes), 480 lbs.

Traits: Bad Sight (Low Resolution); Born Biter 1; Combat Reflexes; Discriminatory Smell; DR 1; Enhanced Move 1 (Ground Speed 18; Costs Fatigue, 1 FP/second); Limited Camouflage; Night Vision 3; Parabolic Hearing 1; Quadruped; Silence 1; Ultrahearing; Vibration Sense (Air; Short Range 1); Wild Animal.

Skills: Brawling-14; Stealth-14; Survival (Woodlands)-14; Wrestling-14.

Techniques: Targeted Attack (Brawling Bite/Neck)-12.

Smilodon populator

ST 18; DX 11; IQ 4; HT 13.

Will 11; Per 12; Speed 6.00; Dodge 10; Move 8.

SM +1 (2 hexes), 700 lbs.

Traits: Bad Sight (Low Resolution); Born Biter 1; Combat Reflexes; Discriminatory Smell; DR 1; Enhanced Move 1 (Ground Speed 16; Costs Fatigue, 1 FP/second); Limited Camouflage; Night Vision 3; Parabolic Hearing 1; Quadruped; Silence 1; Ultrahearing; Vibration Sense (Air; Short Range 1); Wild Animal.

Skills: Brawling-14; Stealth-14; Survival (Plains)-14; Wrestling-14.

Techniques: Targeted Attack (Brawling Bite/Neck)-12.

Super-science Options for Modular Mecha

Yet more options for David Pulver’s Modular Mecha (Pyramid volume 3 issue 51).

Reactionless Thrusters (TL 10^, 1 DP): Allow flight as for jump jets, but do not require fuel. Instead, each second of use consumed energy equivalent to one shot from a beam weapon.

Force Screen (TL 10^, 1 DP, can be taken twice): Gives ablative DR equal to the lower DR for the mecha’s base model (e.g. DR 600 for a standard light mecha). These early force screens are less efficient than the TL 11^ ones in Ultra-Tech: they consume energy equal to one beam weapon shot every second they are active and the mecha counts as moving if they are shut down and regenerating. Alternatively, they may be velocity screens which consume energy equal to one beam weapon shot only when activated by an incoming attack (this is sufficient to remain active for one second).

Transformation (TL 10^, 1 DP, can be taken twice): The mecha can change shape into a different style of vehicle, gaining the Alternate Form advantage. A mecha’s arms and legs may not be used while transformed.

Boat: Water Move 4/32.

Plane (requires Jump Jets): Air Move becomes 20/320.

Rotorcraft: gains Flight (Winged) with Air Move 3/96.

Spacecraft: (requires Jump Jets): Space Move unchanged, but +1 to Hnd and SR while in free-fall.

Submarine (requires Submersible): Water Move 3/24.

Tracked Ground Vehicle: Ground Move 3/36.

Wheeled Ground Vehicle: Ground Move 2/64*.

Jump Jet Options for Modular Mecha

Yes, I'm on a roll with adding new options for David Pulver’s Modular Mecha (Pyramid volume 3, issue 51).

Chemical Rocket: A simpler and lighter design than a nuclear rocket, but less fuel-efficient. Performance and endurance is the same as standard jump jets (they use a smaller motor and carry more fuel), but the mecha gains the Fragile (Flammable) disadvantage, and each extra tank of fuel adds only 40 seconds of endurance (800 yards/second ΔV). However, the exhaust is cooler and not radioactive. Reduce exhaust damage to 6d and the bonus to detect it with infrared to +2.

Ducted Fan: Requires no fuel and has a cool exhaust (damage becomes 3d crushing dkb, no bonus to detect with infrared) but needs a lot of power and only works in an atmosphere with density of 0.1 atmospheres or greater. Move is the same as standard jump jets, but treat each second of use as one shot from a beam weapon.

Fusion Rocket: A weaker but more efficient nuclear rocket only suitable for space travel. Gives 0.09 G (1 yard/second²) acceleration and 5 miles/second ΔV. Each additional fuel tank adds another 20 miles/second ΔV. Use Piloting (Low-Performance Spacecraft).

HEDM Rocket: High-Energy Density Materials are highly unstable, but give better fuel-efficiency than conventional chemical rocket fuels. Performance is the same as standard jumpjets but endurance increases to 80 seconds (1,600 yards/second ΔV) and each extra tank of fuel adds another 120 seconds (2,400 yards/second ΔV). The exhaust is no cooler than that of a nuclear rocket, but isn’t radioactive at least. The mecha also gains the Volatile feature without any reduction in DP.

Jet Engine: A turbojet with afterburner is heavier than a nuclear-thermal rocket of the same thrust, but more fuel-efficient. Performance in air is the same as standard jump jets, but endurance is increased to 5 minutes and the exhaust has the same benefits as that of chemical rockets. The mecha gains the Fragile (Flammable) disadvantage, and can only fly in an atmosphere containing oxygen with at least 0.1 atmospheres pressure. Each additional fuel tank adds 20 minutes endurance.

Nuclear Air-Ram: Although barely capable of take-off in standard gravity, and useless anywhere without an atmosphere, this gives an endurance of one year! Reduce air move to 12/48.

Note: the numbers given are only somewhat consistent with those in sources like GURPS Spaceships and GURPS Vehicles, and weren’t really checked carefully. In the kind of cinematic setting which flying mecha are expected to exist in, this shouldn’t be too much of an issue. Back-of-an-envelope calculations suggest that the existing jump jet rules are extremely generous. A more realistic (and still fairly generous) take would reduce air move to 12/48 (nuclear air rams would drop to 7/36, making them incapable of vertical take-off on Earth).

More Features for Modular Mecha

A few new options for David Pulver's Modular Mecha (Pyramid volume 3 issue 51).

Access Space (1 DP): The mecha has a relatively roomy interior, allowing crew to carry out repairs without leaving the vehicle.

Grippers (−1 DP): The mecha has crude gripping claws instead of hands. Treat it as having Bad Grip 1 and Ham Fisted 2 (instead of Ham-Fisted 1)

Electromagnetic Armor (1 DP): This system draws on the mecha’s internal energy bank in the same way as a beam weapon. It activates automatically when the mecha is hit and stays active for 1 second, consuming one ‘shot’ of energy. During that time the mecha’s DR is tripled (instead of doubled) against shaped charge and plasma attacks. May not be taken alongside the No Laminate feature.

Enhanced Reactor (1 DP): The rate at which the mecha's energy bank recharges is doubled (i.e. 1/15 of full capacity every second).

Expendable ECM (1 DP): Numerous small launchers capable of deploying chaff, decoys, expendable jammers, and smoke. When activated gives −10 to all electromagnetic senses (including normal vision, hyperspectral vision, thermal imaging, and radar) within a 50 yard radius (centered up to 50 yards from the mecha) for 1 minute. Can be used 4 times (reloads are 200 lbs. $5,000 per use).

Extra Arms (1 DP, can be taken twice): The mecha gains an extra arm. Alternatively, it gains two additional arms, but they have the limitations given for Short Arms (below).

Extra Energy Banks (1 DP, can be taken twice): The mecha gets three times as many shots from its beam weapons and triples endurance when operating on auxiliary power. This increases to five times as many shots and quintuple endurance if this feature is taken twice. Recharge is still only 1/30 of the original figure (i.e. it takes 90 or 150 seconds of inactivity to recharge fully).

Inferior Sensors (−1 DP): All sensors have their range or magnification halved. Reduce any Acc or skill bonus by 1.

Jumping Legs (1 DP, can be taken twice): Extra-powerful leg motors grant Super Jump 1.

Short Arms (−1 DP): The mecha’s arms all gain the Short and Weak (half body ST) limitations. They may not have weapons mounted in them, but may carry them if their ST is sufficient.

Superior Sensors (1 DP): All sensors have their range or magnification doubled. Increase any Acc or skill bonus by 1.

Unstabilized (−1 DP): The mecha lacks advanced stabilization systems, so it does not have the benefit of weapon stabilization and reduces its SR by 1.

Weak Strikes (−1 DP): The mecha has no Striking Strength bonus.

Wings (2 DP): A set of folding wings grants Flight (with the Gliding and Winged limitations). Add Wi to the mecha’s hit locations. Wings have DR 30. Most useful when combined with jump jets, doubling endurance in atmosphere.

Bigger Modular Mecha

The mecha in Modular Mecha (Pyramid volume 3 issue 51) are fairly small (17-33 feet tall and 25-65 tons) compared to those seen in some franchises. For example, Gundam mobile suits are about 60 feet tall, pacific rim jaegers are 240-280 feet tall, and Warhammer 40,000 titans range from 40 foot tall ‘scout’ titans to the imperator class, which are at least 200 feet tall.

To make a ‘giant’ mecha, increase SM by 2, decrease Hnd by 1, double height, ST, HP, and DR, and multiply LWt. Load and Cost by 8.

A ‘colossal’ mecha increases SM by 4, reduces Hnd by 2, multiplies height, ST, HP, and DR by 5, and LWt. Load and Cost by 125.

A ‘titanic’ mech increases SM by 6, reduces Hnd by 3, multiplies height, ST, HP, and DR by 10, and LWt. Load and Cost by 1,000.

The mass of weapons carried can increase by the same factor as Load. A simple rule of thumb for scaling up weapons: multiply calibre, damage, range, and ST by the same factor used for the mecha’s height, ST, HP, and DR (e.g. a giant particle beam does 5d×40 (5) damage, has Range 12,000/36,000, and ST 200). Raise Acc by the amount the mecha’s Hnd was reduced (e.g. +1 for a giant weapon) and increase Bulk by the increase in the mecha’s SM (so giant weapons have Bulk −12). Weight and cost increase by the same factor as the mech’s.

Alternatively, a mecha can mount an array of smaller weapons instead of one big one. A giant mecha can mount 8 normal mecha weapons instead of one giant one. A colossal mecha can mount 10 giant-sized ones instead of one colossal one, and a titanic mecha can mount 8 colossal weapons instead of one titanic one. Such weapons are usually linked, so simply multiply RoF and shots by the number of weapons.

A giant mecha can have up to 4 crew without taking the Occupancy +1 feature, while a colossal one can have up to 25 crew and a titanic one up to 100. This number can be doubled by taking an Increased Occupancy feature (this is identical to Occupancy +1 except it adds more crew stations). Whether additional crew are actually required depends heavily on the setting.

Movement is also setting dependent. In some, even very big mecha move like humans, so multiply Move by the same factor as height, ST, etc. In others, larger mecha are slower and more ponderous: Move becomes 8/12 for giant mecha, 5/10 for colossal ones, and 3/9 for titanic ones. The Move ±5 feature becomes Move ±2/3 for giant mecha, Move ±2/4 for colossal mecha, and Move ±1/3 for titanic mecha. Jump jet movement is typically not adjusted for size.

Multiply the range of any sensors or communication systems by the same factor as the mecha’s height, ST, etc. The Acc bonus they grant is increased by the same amount as the mecha’s Hnd was reduced by.