Grey Matter is a Galvan – a tiny but super-intelligent alien. When Ben is Grey Matter, his diminutive size allows him to slip past most attackers and his increased brainpower can solve some of the most complex problems.
Find out more about Ben 10 Destroy All Aliens characters. With the help of his cousin Gwen, his granpa Max and his alien buddy Tetrax ten-year-old Ben Tennyson is now fighting against Mechamorph Warrior. Check out their character profiles on the Cartoon Network official show page for Ben 10 Destroy All Aliens.