Grey Matter

Grey Matter is the Codon Stream's DNA sample of a Galvan from the planet Galvan Prime/Galvan Mark II.

Appearance
Grey Matter is a gray-skinned, frog-like, bipedal alien, only six inches tall with large green eyes with little minus sign like pupils.

Grey Matter wears a white jump suit with a line going down it.

In the original series, Grey Matter wore the Omnitrix symbol on his back. In Ultimate Alien, Grey Matter wears the Ultimatrix symbol on his chest.

Gwen as Grey Matter has Gwen's hair and has more oval shaped eyes with much smaller pupils. She wears light blue pants and top with dark blue sleeves. She wears the Omnitrix symbol on her back.

Powers and Abilities
Grey Matter's size belies his great calculative and technical intellect. He can create almost anything from spare parts and know the function of any device at a glance. Grey Matter's intellect serves as a problem solver and analytical help in difficult situations. Additionally, he can sometimes control living things by stimulating certain parts of their anatomy, if such beings can be controlled by external stimuli. His size allows him to squeeze into small spaces and he can climb walls thanks to tiny suction cups on his skin. He also has sharp teeth and his slimy skin makes him difficult to grab.

Weaknesses
Grey Matter's size makes him unsuitable for battle and as such he must outsmart his enemies in a fight. Animals like dogs pose another problem as they may see him as a possible meal.

Ben 10 and Ultimate Alien

 * Grey Matter first appeared in Washington B.C., Grey Matter was searching in cereal boxes for a Gold Sumo Slammer card.
 * In Hunted, Grey Matter defeated Kraab and Sixsix.
 * In A Small Problem, the Omnitrix malfuntioned, trapping Ben as Grey Matter for most of the episode. Grey Matter snuck onto a water slide and got captured by Howell Wainright.
 * In Secrets, Grey Matter appeared when the Omnitrix malfuntioned. He defeated one of Vilgax's drones.
 * In Truth, Grey Matter defeated a Null Guardian.
 * In Grudge Match, Grey Matter defeated one of Slix Vigma's drones.
 * In Ultimate Weapon, Grey Matter snuck into a house, let Gwen and Max come in and opened a safe.
 * In They Lurk Below, Grey Matter saved a drowning man.
 * In Ghostfreaked Out, Grey Matter appeared.
 * In Back With a Vengeance, Grey Matter appeared 8 times.
 * In Midnight Madness, Grey Matter was hypnotized into being Gwen's slave.
 * In Merry Christmas, Grey Matter accidently destroyed the Rustbucket's air conditioner and later destroyed the Jingleator.
 * In The Unnaturals, Grey Matter appeared.
 * In Be Afraid of the Dark, Grey Matter escaped Zs'Skayr and built a sungun.
 * In Perfect Day, a dream Grey Matter defeated a mutated dream Cash and J.T.
 * In Ken 10, an alternate timeline Grey Matter was used by Kenny to escape his room and later, to unlock his Omnitrix's Master Control.
 * In Ben 10: Secret of The Omnitrix, Grey Matter defeated Dr. Animo.
 * In Ben 10: Race Against Time, an alternate timeline Grey Matter caused trouble in a diner.
 * In Snack Break, Grey Matter failed to retreive his snack in a vending machine.
 * In Ben 10,000 Returns, Grey Matter was unlocked by Ben 10,000.
 * In Double or Nothing, by Albedo.

Ben 10

 * Washington B.C. (first appearance)
 * Hunted
 * A Small Problem (accidental transformation; selected alien was Ripjaws)
 * Secrets
 * Truth (accidental transformation; selected alien was Four Arms)
 * Grudge Match
 * Ultimate Weapon
 * They Lurk Below (accidental transformation; selected alien was Ripjaws)
 * Ghostfreaked Out
 * Back With a Vengeance (8x) (last time the selected alien was Stinkfly)
 * Midnight Madness (under hypnosis)
 * Merry Christmas (2x) (last time the selected alien was Four Arms)
 * The Unnaturals (accidental transformation; selected alien was XLR8)
 * Be Afraid of the Dark (acciendental transformation)
 * Perfect Day (accidental transformation; selected alien was Heatblast)
 * Ken 10 (used by Kenny Tennyson)(alternate timeline's Grey Matter)
 * Ben 10: Secret of The Omnitrix (accidental transformation; selected alien was Stinkfly)
 * Ben 10: Race Against Time (accidental transformation; selected alien was Four Arms) (alternate timeline's Grey Matter)
 * Snack Break

Ben 10: Ultimate Alien

 * Double or Nothing (by Albedo)

Trivia

 * Grey Matter has the most accidental transformations.
 * In Ken 10, Kenny uses Grey Matter's intelligence to access his Omnitrix's Master Control.
 * Grey Matter is the same species as the Omnitrix's creator, Azmuth.
 * Grey Matter is Ben's second smallest form, smallest is Nanomech.
 * Grey Matter has the most appearances in Back With a Vengeance. This is ironic considering Ben dislikes Grey Matter for fights. However, most times Ben did use Grey Matter actually were for escape methods.
 * Grey Matter doesn't always know what he is talking about.
 * It was revealed that it was not Azmuth or Albedo who contributed their Galvan DNA to the Codon Stream to make Grey Matter.
 * Grey Matter is the only alien that still has clothes that are similar to 10 year old Ben's.