He is voiced by Ben Diskin.
Numbuh 2 is the 2x4 technology specialist of Sector V. He wears a sky blue shirt, brown pants, black and white sneakers, an aviator's hat with yellow flying goggles and the number 2 on it, and he has auburn hair under his hat, which is rarely removed.
Being Sector V's mechanical genius, Numbuh 2 is described as one of KND smartest operatives, but is jokingly called a "nerd" by his teammate Numbuh 5, as he frequently plays with Yipper Cards with Numbuh 4, and watches Doctor Time Space and the Continuums with the other kids of the KND.
Numbuh 2 is in charge of building most of the 2x4 Technology in his team; he even built Sector V's Treehouse. In Operation: A.M.I.S.H., it is stated that Numbuh 2 loves technology above anything else, to the point he begged Numbuh 1 to take him back to the Treehouse and clung to Numbuh 1's leg when he was forced to stay in Sector A, a Sector that doesn't use technology, due to the fact they are Amish.
In the same episode Numbuh 1 hints further at Numbuh 2's intelligence and inventing skills by stating that if the Splinter Cell gets thier hands on Numbuh 2, they could build almost anything. This insinuates Numbuh 2 has a greater intelligence than even most Science Officers and Research personnell.
He also has a great interest in food, especially in chili-dogs, as seen in Operation: D.O.G.F.I.G.H.T., and is the only person who is able to eat Grandma Stuffum's grotesque food. In this same episode, Numbuh 2 is shown to love flying and would occasionally refers to himself as "King of the Skies." In Operation: S.P.I.N.A.C.H., it is revealed he is the only character in the show who likes spinach, while everyone else finds it disgusting.
While off on KND business, Numbuh 2 has a knack of playing detective, as seen in Operation: P.I.N.K.-E.Y.E., Operation: C.L.U.E.S., Operation: S.P.A.N.K.E.N.S.T.I.N.E. and Operation: C.R.I.M.E. . According to him, he used to be partners with Joe Balooka, one of the Hall Monitors at Gallagher Elementary School, before he joined the Kids Next Door.
As seen throughout the show, Numbuh 2 acts as the comic relief of the team alongside Numbuh 3 and Numbuh 4, making jokes and cracking puns that he thinks that are funny, but are not to anyone else in the show. As a result, Numbuh 5 would often hit him with her trademark hat or complain about his comments. In effect, his counterpart, Negative Numbuh 2, is considered funny by everyone, except for Numbuh 2 himself.
Numbuh 2 is close to his baby brother, Tommy Gilligan, despite the fact he finds him annoying most of the time as seen in Operation: T.O.M.M.Y. and Operation: T.R.I.C.Y.C.L.E.. According to Numbuh 1, Numbuh 2 taught Tommy how to build ships before Tommy became a KND operative.
- He share voice actor with Nigel Uno / Numbuh 1 and Little Traitor Dudes For Children's Defense.
- His Voice Actor, Ben Diskin is best known voicing as Sai from Naruto Shippuden, Stitch from Stitch!, Joseph Joestar from Jojo's Bizzare Adventure: Battle Tendecy, Eugene Horowitz from Hey Arnold! Seasons 2-5, Humphrey from Alpha and Omega sequels, Spook from Top Cat movies and Carapace, Pegasus, Nooroo and Sass from Miraculous Ladybug: Tales of Ladybug and Cat Noir.