Atenilae are a prehistoric Companion of Avalon, brought back to modern day through the efforts of science and magic. They are like a theropod, but often have a more mammalian face, as well as small, delicate front paws. Their hindlegs, on the other hand, are large with flattened feet, perfectly built for running at high speeds for long distances. Along with a tail to balance them, their large size and sturdy build works well in being a suitable mount for any curious adventurer. Incredibly hardy, they can go on for ages without food or water, seemingly only satiated through head pats and snuggles.
The magic of an Atenilee comes from the fact it isn't organic. It's composed of an endoskeleton as well as an outer shell made of synthetic material, yet it moves, acts, and feels as though it is completely alive, capable of feeding and hydrating like a real animal.