Grey Matter is the Omnitrix's DNA sample of a Galvan from the planet Galvan Prime. Ben 10K's Grey Matter's design was created by Rafael Santos.
Grey Matter is a grey-skinned, frog-like, bipedal alien that is only four inches tall with large green eyes, which have rectangular pupils and horizontal eyelids. He wears a black, white and green suit, alongside extended black and white fingerless gloves. He has a green box marked with a green 10 on his back. He also wears a white labcoat. The Omnitrix symbol is located on his chest.
Powers and Abilities
Grey Matter's small size belies his great calculative and technical intellect. He can create complicated machines from spare parts, understand the function of any device at a glance, and make sophisticated repairs to complex machines (such as a warp-drive engine). Grey Matter's intellect serves as a problem solver and analytical help in difficult situations. This allows Grey Matter to think more strategically when brute force is inefficient. In fact, Grey Matter is smart enough to know how to unlock the original Omnitrix's Master Control.
Grey Matter's brain capacity makes Ben smarter about things he's never even seen before, like Kraab's alien circuitry. Grey Matter can sometimes manipulate living things by stimulating certain parts of their nervous system if such beings can be controlled by external stimuli. Grey Matter's size allows him to squeeze into small spaces and can climb walls due to microscopic pads on his skin. He also has sharp teeth and his slimy skin makes him difficult to grab.
Grey Matter is amphibious and has gills. Grey Matter has a long prehensile tongue, owing to his insectivore nature. As a Galvan, he also possesses a 'pre-brain' which deals with all basic bodily functions.
Grey Matter's small size makes him unsuitable for physical battle, so he must outsmart his enemies in a fight. Animals like dogs and cats can be a problem, as they may see Grey Matter as a chew toy or food to them.
Despite possessing immense intelligence, Grey Matter can still make miscalculations. According to himself, Grey Matter sometimes does not know what he is talking about and he does not know everything, as seen when he did not know (at first) which galaxy his species is from.
Being a Galvan, Grey Matter would be vulnerable to his natural predator, the Omnivoracious, if the latter's species was not extinct.