Dexter looks a typical boy expect he wears a lab coat, and gloves. This seems to be his typical outfit and he has red hair.
Dexter appeared as an ally to Dib and his pals in Slade Strikes Back. After the adventure he decided to retire and live normally but he left retirement after The Great Time Travel Adventure and is going to join Lizbeth, Milo and Boomer in The Child Avengers
Dexter finally returns here and he works with Dib again but this time to stop their unknown enemies Discord and to a lesser extent Sigma. Dexter joins the Membrane Elite and works with the team as mission control mostly since he's a scientist as opposed to a fighter. Dexter advises the team in their fights to save the Republic and Dib, Boomer and X's leading against Loboto. He then somehow learns Discord's true plan with Sophitia and then he and Hiscord seal 18 in a unbreakable shield after Noir's plan goes as planned.
He is given the cure from Cassandra which works on 18.
Dexter is an arrogant class know-it-all, and prides himself on rarely being proved wrong. This is contradicted by his experiments being duds. He is prone to believing urban myths that are fed to him, which often cloud his judgment and superstitions.He also struggles to fit in with others not uncommon with kid heroes. as his intelligence and arrogance drives others away.
Strangely he and Gosalyn share a voice actor much like Bender does with Hans and the Joker.
Allies: Dee Dee, Dib, Bubbles, Bender, Milo, Lizbeth, Darkwing Duck, Gosalyn, Edd, Daxter, Peep, Luciaus, Dr. Doofenschimtz, Stewie, Dr. Blowhole, Oscar, Emperor X, Starfire, Skipper, Jorgen Von Strangle, Jimmy Neutron, Raz, Crypto, R.J., Cassandra, Android 18, Sagat, Delta Squad, Megaman X, Hiscord, Yakko, Wakko, Dot, John Price
Enemies: Mandark (though not anymore if he learns Mandark changed his ways), Slade, Anti Cosmo, the Joker, Discord, the Dystopia League, Sigma, the Sigma Organization
Voiced by: Christine Cavanaugh