Stinkfly (voiced by Dee Bradley Baker) is the 7th alien to appear on the show. Another of Ben's more commonly used forms, Stinkfly is a Lepidopterran from the planet Lepidopterra (a play on lepidoptera, the scientific name for butterflies and moths).


In any situation requiring flight, Stinkfly is Ben's alien of choice. Stinkfly's thin, rapidly flapping wings allow him to move at high speeds in the air and dodge attacks just as quickly. Stinkfly also possesses disproportionate strength, enough to carry people and objects heavier than himself. Stinkfly's four eye stalks give him a wide range of vision from the sky, including the ability to look directly behind himself.

For attack, Stinkfly can excrete high-pressure streams of liquids from the pollen ducts in his eye stalks and mouth. The type of liquid can range from a flammable toxin to an immobilizing jelly. In "Don't Drink the Water", Ben's child form of Stinkfly (Stinkyfly) could emit a powerful herbicide gas through flatulation. For melee combat, Stinkfly has a sharp tail and four pincers in its legs.


Like most insects, Lepidopterrans are extremely vulnerable to any kind of chemical poison or gas. Although their exoskeleton bodies are fairly strong, their wings are extremely fragile and easy to damage. Water is especially a problem for Stinkfly as it can render him incapable of flying if too much of it wets his wings.

Furthermore, he is unable to swim due to the small surface area of his limbs. A more minor inconvenience is Stinkfly's intense body odor (hence the name), so hiding can be a problem when Ben transforms into Stinkfly.


Lepidopterra is a swamp planet home to a wide variety of giant plants, and hence much larger insects evolved to match. Meant to be a combination of various Earth insects (dragonflies, crickets, and praying mantis' specifically). Lepidopterrans are an intelligent insectoid race that reside in a complex of giant hives, each ruled by its own queen.

Ben 10:Ultimate AlienEdit

His eyes are green and the Ultimatrix is now on his chest.