Grey Matter

GREY MATTER
Grey Matter (voiced by Richard Steven Horvitz) is a Galvan (the former a play on actual grey matter and Greys, the latter a play on galvanization) from the planet Galvan Prime. Galvan Prime is a tiny world by most standards (the series does not give a definitive measurement), and hence Galvans are on average about five inches tall.[6]

Galvans are bred to be naturally intelligent and intuitive, learning quickly about any given object from just a simple glance. Their bodies are designed for the same purpose: soft, flexible bones and slimy skin allow Galvans to squeeze into all but the smallest of spaces. It also makes grabbing them somewhat difficult. Their slimy skin also allows them to stick to most surfaces. Regardless, Grey Matter is easily stomped on because of his small size.[6] Not built for combat, Grey Matter evades and outsmarts his enemies, rather than fighting them head on. As Grey Matter, Ben benefits from the form's specialized breeding, giving him the ability to instantly understand any technology. Showing a more light-hearted side of the Omnitrix, Ben, despite being able to understand any device, does not consciously comprehend what he is doing, leading him to remark as much.

Ben 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. Since then, Grey Matter has been his form of choice when needing to be stealthy or intelligent, but has also been a popular target for accidental transformations, such as in "A Small Problem".