He is characterized by his large size; as well as by an herbivorous diet; a thick protective skin, formed from layers of collagen positioned in a lattice structure; a relatively small brain for Rhinocerodon this size; and two horns. He generally eats vegetation, although his ability to ferment food in his hindgut allows Rhinocerodon to subsist on more fibrous plant matter, if necessary. Unlike other animal Psymonsters, he lacks teeth at the front of his mouth, relying instead on his lips to pluck food.
He is a large, very obese gray rhinoceros with blue eyes and white horns.
- Rhinocerodon, along with Exodus, Kitsumo, Gigantoceratops, and Greedy, are the only obese Psymonsters.