Wildmutt

Wildmutt (voiced by Dee Bradley Baker) is a Vulpimancer from the planet Vulpin (a play on vulpine, which means fox). Vulpin is a pitch black planet at the edge of the galaxy, used as an intergalactic dumping ground. The ecosystem of the planet has been poisoned beyond repair because of this, and as such the few creatures that survive here do so under subzero temperatures. Vulpimancers are one of the few creatures to survive on Vulpin, living in deep underground caves, and are no less mutated than the planet itself.[23]

Ranging from human size to several times that, Vulpimancers share few common characteristics. Their only common feature is the general shape of their bodies, being a cross between a lion and a gorilla.[17] Ben 10,000's Wildmutt has much more pronounced feline traits, including stripes and a tail. This unique body setup allows Wildmutt to run, jump, and climb objects at high speeds, in addition to making him fairly strong. Since the caves they live in are pitch black, Wildmutt has no eyes, instead having evolved to see through smell and hearing, which is depicted as functioning somewhat like a thermograph sensor. From sound to heat, few things escape Wildmutt's radar-like sight.

According to various profiles on Wildmutt, the porcupine-like quills on his back supplement his senses, acting as finely tuned sense receptors. They are also said to serve as weapons. They can either protect Wildmutt while he's rolling or be fired off as projectiles.[23] The series has not yet addressed this particular ability; furthermore, Gwen has no trouble riding on his back on several occasions.

Because they have no eyes, Vulpimancers do have some trouble with finer movement, and under certain conditions are unable to detect their enemies.[23] Vulpimancers, Wildmutt included, are also unable to speak in any understandable fashion, instead relying on snarls and growls, which can be an inconvenience when trying to avoid conflict. Because he relies on his sense of smell and hearing to see, Wildmutt is sensitive to loud noises and strong smells. He is also rendered useless if his nose or ears are clogged.

Ben first transformed into Wildmutt in "And Then There Were 10" after his second experiment with the Omnitrix. This was Ben's first intentional transformation.