The Kid also known as "Ace", is a slender mysterious Hispanic character whose name is unknown, is meant to be very cool and says that he works alone. He first appeared in Operation: D.O.G.F.I.G.H.T., as a rival pilot to Numbuh 2 and did not speak until the near-end of the episode when they cross paths in Mr. Washer Hobby Shop when he asked for a defense system upgrade. By the end, he and Numbuh 2 had destroyed each other's aircrafts and realized what Mr. Washer had been panning, so they worked together in order to stop him.
In Operation: C.A.K.E.D.-F.O.U.R. he was a part of the Toobathon to win the Delightful Children's birthday cake. At one point he slows down to talk with Numbuh 3 about "sharing decorating tips" after the race. This suggests he might have a mutual attraction to her, but is not confirmed otherwise.