Grey Matter

Grey Matter (voiced by Richard Steven Horvitz in the TV series and by Carlos Alazraqui in the live-action movie) is a Galvan (the former a play on actual grey matter and Greys, the latter a play on galvanization) from the planet, Galvan Prime.

Abilities
Grey Matter's size belies his great calculative and technical intellect and when it comes to intellect he's second to none. He can create almost anything from spare parts and deduce the function of any device at a glance. Also, Grey Matter's intellect serves as a problem solver and analytical help in difficult situations. Grey Matter's diminuitive size allows him to squeeze into small spaces, and he can climb walls thanks to tiny suction cups on his skin. He also has sharp teeth, and his slimy skin makes him difficult to grab.

Weakness
Unfortunately, Grey Matter's size makes him unsuitable for battle, and hence Ben must outsmart his enemies while using the form. Grey Matter has, however, proved very valuable when used, as he is capable of hiding in very tighly compacted areas, and the form's supreme intellect has helped in many situations.

History
Ben officially first transformed into Grey Matter in Washington B.C. when he saw that a gold Sumo Slammer card could be found in a box of cereal. Gwen found him looking for the card in the cereal boxes at the supermarket. Although Ben rarely intentionally selects Grey Matter, he often finds himself in that form as a result of accidental transformations, such as in A Small Problem. Most of these situations occur when Ben intends on transforming into a large, powerful alien, making his change into Grey Matter all the more ironic. It seems that Grey Matter is the one with the most accidental transformations. As Azmuth was the one who made the Omnitrix it is possible it is his DNA that is in the watch.

Appearance
Grey Matter is a gray-skinned, frog-like, bipedal alien only six inches tall with large green eyes. The Omnitrix is located on his back.

Possible Future
Grey Matter may just look like Azmuth, the creator of the Omnitrix because Ben transforms into Grey Matter as a 10 year-old, and Azmuth is older, so he must have mustache-looking the one older Galvans have. In Ben 10,000, he wears black in his body and maybe in the Galvan form.

Race Against Time
Greymatter appeared briefly in Ben 10: Race Against Time, where, after getting mocked by his peers in a popular hangout, Ben transformed into Greymatter, and rearranged the circuits of the machines in the diner to create havoc.