Grey Matter is one of Ben Tennyson's alien egos from the original Ben 10 Series.
He is the Omnitrix's DNA sample of a Galvan from the planet Galvan Prime.
In the original series, He is voiced by Richard Steven Horvitz who also voiced Billy, Daggett the Beaver, Lugosi, Zim and Alpha's 5 and 7, Carlos Alazraqui in Race Against Time and Eric Bauza in Omniverse.
He is a Galvan, a gray frog-like alien that is five inches tall. The Galvans are a highly intelligent race responsible for many of the technologies shown in the series, including the Omnitrix, the Null Void Projector, the Null Void, their planet, Galvan Mark II (since the Highbreed destroyed their original homeworld, Galvan Prime, in the "Alien Force" two-parter "War of the Worlds"), and the Galvanic Mechamorphs (Upgrade's species).
Powers and Abilities
- Enhanced Agility: Due to his small size, Grey Matter is easily able to dodge attacks.
- Wall Crawling: Grey Matter can climb up vertical slopes with ease.
- Underwater Breathing: Grey Matter has gills which allow him to survive underwater.
- Manipulation: Through his opponent's pressure points, Grey Matter is able to manipulate their body into doing what he wants. He has used this ability on creatures such as sharks and Null Void Guardians.
- Hephaestan Neuro Grip: Using this technique Grey Matter can incapacitate "all manner of prey".
- Enhanced Intelligence: Grey Matter's species is one of the smartest in the galaxy. A notable of this intelligence is when he was able to easily shut down a machine that could affect climate change and make it snow all year in the desert, manipulate a person's nervous system, mutate children into elves, grant reindeer flight capabilities, control dozens of guards and manipulate the fabric of time itself all at once.
- Enhanced Reflexes: Grey Matter was able to jump off the 'Test your Strength' machine just as the platform hit the bell.
- Technological Prowess: Grey Matter was able to invent a "sun gun" with only a few scraps and a few minutes.
Ben first intentionally transformed into Grey Matter to search for a rare gold Sumo Slammer Trading Card in cereal boxes in Washington B.C..
In Hunted, Grey Matter defeated Kraab and SixSix.
In A Small Problem, the Omnitrix malfunctioned, trapping Ben as Grey Matter for most of the episode as he was trying to escape Howell.
In Secrets, Grey Matter defeated one of Vilgax's drones before the malfunctioning Omnitrix turned him into Upgrade.
In Truth, Grey Matter defeated a Null Guardian and sent Phil to the Null Void.
In Grudge Match, Grey Matter disabled the alien prisoners' shock implants, looked for the escape pod controls and defeated some of Slix Vigma's drones with Kevin 11.
In Ultimate Weapon, Grey Matter snuck into a building and helped Gwen and Max to get in. He then opened a safe to retrieve the Mask of Ah Puch and escaped from Enoch and the Forever Knights.
In They Lurk Below, Grey Matter saved a drowning man from some sharks.
In Ghostfreaked Out, Grey Matter fought the Circus Freak Trio and hid from Zs'Skayr.
In Back with a Vengeance, Grey Matter appeared about eight times. Firstly, he appeared when Ben unlocked the Master Control. Then, he appeared in a photo. Later, Grey Matter escaped from Vilgax's grip while he and Kevin 11 where arguing. In the Null Void, Grey Matter was used several times to evade Vilgax and Kevin. At the end of the episode, Ben accidentally transformed into Grey Matter, having just remembered that the Master Control was once again locked.
In Midnight Madness, Grey Matter was hypnotized into being Gwen's slave.
In Merry Christmas, Grey Matter accidentally destroyed the Rust Bucket's air conditioner and later (intentionally) destroyed the Jinglelator.
In The Unnaturals, Grey Matter stopped some thieves from stealing the Liberty Bell and won an MP3 player in a contest.
In Be Afraid of the Dark, Grey Matter evaded Zs'Skayr and Viktor, explained the former's plan to Max and Gwen, and built a Sun Gun.
In Ben 10: Secret of the Omnitrix, Grey Matter defeated Dr. Animo.
In Perfect Day, Grey Matter defeated a mutated Cash and J.T. in a dream.
In Ben 10: Destroy All Aliens, Grey Matter escaped Retaliator and ran back to his house, where he was attacked by Carl and Sandra before the Omnitrix switched him into Diamondhead.
Ben 10: Ultimate Alien
Grey Matter appears in the intro, in Ben 10'000 Returns, Grey Matter along with the rest original series and some new aliens that Ben never used before were unlocked by Ben 10,000, but 16 year old Ben never used Grey Matter in any of the episodes.