Ben Tennyson in his Grey Matter form. The Galvans are an alien race from the planet Galvan Prime. Ben Tennyson can transform into a Galvan with his Omnitrix. While in this form, he's known as Grey Matter. Appearance Batman and Grey Matter References ↑ As seen in Batman and Grey Matter. Retrieved from "https://superfriends.fandom.com/wiki/Galvan?oldid=30478" Categories: Alien Races Species DC Comics Community content is available under CC-BY-SA unless otherwise noted.