This illustration is from my Kickstarter project to create drawings of all of the friendly nonhumans and land animals from Professor M.A.R. Barker's wonderful Tékumel (aka Empire of the Petal Throne) role-playing world setting.
"These great, slow-moving six-legged beasts have flattish, horned heads with a splayed beak. The Chlén will fight only if attacked, and if it is reduced to one or zero hit points, it is subdued and can be domesticated by an animal trainer. Their horny integument is the universal substance for armor and weapons; once treated with secret processes to mold it, another series of processes harden it into something just a little softer than iron. Pieces of Chlén-hide are taken from a living animal, and it then takes two weeks for the animal to regenerate it, much as a human grows back a fingernail. Chlén can be used to pull carts, once tamed, but their slowness makes them usable mainly for loads which are nonperishable and not needed in a hurry. Most transport on Tékumel is done by bearer-slaves."
Pocket Universe System: Quicksilver, Teenage Demon Slayers
Habilis System: Cavemaster