Numbuh 555 is a 21 year old dude who was recently sent undercover by KND. Most of the operatives know him very well. Not scared for a fight. Good friends with Sector V. Helps Numbah 5 in missions when needed due to numbah 1 leaving to space. Huge enemies with Toiletnator after ruining his ship in battle.
Numbuh 555 is a friendly guy but in battle he's the opposite. He is never seen without her teddy bear (teddy) which he keeps close after getting on his fifth birthday. When it is taken away he can unlease a attack strong enough to knock out a grown man or gorilla. Great at building 2×4 technology but is terrible with modern tech.
Numbuh 555 is usually dressed in a red t-shirt jeans black boots, spikey hair and sun glasses . He sometimes wears a black cap for good luck in battle.