Wildmutt is the Omnitrix's DNA sample of a Vulpimancer[3][4][5] from the planet Vulpin.[Bandai 1]

Wildmutt appears to be a large orange dog-like creature with no eyes, ears, nose, or tail. He stands on all fours and his movements are somewhat apelike. His teeth are very defined and his bottom jaw sticks out of his mouth. The various spines found all across his body function similarly to whiskers with tactile sensing, and are not fur.[DJ 1] Since Wildmutt has no eyes, he uses his sense of smell and hearing to navigate, which are aided by three gill-like nostrils located on each side of his neck.

In the Original Series, Wildmutt wore a black-and-white brace with the original Omnitrix symbol on his left shoulder.

While under the effects of a cold in Side Effects, Wildmutt's fur discolors from its vivid orange to a pale yellowish-orange tone, and his lips and claws turn from black to a sickly dark green hue.

In Back With a Vengeance, Wildmutt wore a yellow raincoat.

In Merry Christmas, Wildmutt briefly wore fake antlers while disguised as a reindeer.

In Don't Drink the Water, 4-year-old Wildmutt, nicknamed Wildpup, looked very similar to his 10-year-old self, but a lot smaller and thinner nails instead of claws.

In Destroy All Aliens, Wildmutt's skin was lighter and his fur was more defined.

In Race Against Time, Wildmutt looks the same, except his skin is darker.

In Ultimate Alien, 16-year-old Wildmutt looks mostly the same except his skin is lighter in color. While his lips were still black in the Ultimate Alien intro, they were in the same color as his fur in the actual series. He wore the Ultimatrix symbol on his chest. Kevin as Wildmutt shares these traits.

In The Forge of Creation, 10-year-old Wildmutt looked mostly the same as in the Original Series, except his lips were in the same color has his skin, his shoulder brace did not have any white on it, and the original Omnitrix symbol was recolored green.

In Heroes United, 16-year-old Wildmutt looked exactly the same as in the Original Series but his skin was a darkish orange.

In Omniverse, Wildmutt's lips have returned to being black and his forearms are a bit bigger. 16-year-old Wildmutt wears a green and white collar with the Omnitrix symbol.

11-year-old Wildmutt looks closer to his appearance in the Original Series than 10-year-old Wildmutt in Ultimate Alien, with the white returning to the shoulder brace, though the Omnitrix symbol is still colored green.