Wallabee Beetles

"Are you a man? Or just a kid? Well, if so, then I'm a man, but Numbuh 4 is just a kid though. This Aussie's just here to help me wipe out these pesky Coalition of the Red Star nutcases."

-Su Ji-Hoon, Operation: D.O.O.M.S.D.A.Y.

Wallabee "Wally" Beetles aka Numbuh 4 is the brash and impulsive hand-to-hand combatant Australian boy of Kids Next Door Sector V. He is close friends with Hoagie and has a crush on his teammate, Kuki, who is his close friend and teammate and who returns his feelings. He ends up marrying Kuki in the future. There are few amongst the KND that can match him in hand-to-hand combat, and even fewer who can compete with his bravery. Numbuh 4 is also known for his apparent lack of intelligence, preferring to simply beat up any and all obstacles in his way.

In When the Cold Breeze Blows Away, he is a brawler of the Kids Next Door. Also, while he's still married to Kuki, he went back to his 7-year old self, and is looking to improve his intelligence.​​​​​