The final episode of Kids Next Door (Operation: G.O.O.D.B.Y.E.) sees the team seemingly replaced by other good cartoons.
(The Delightful Children, Father, and other KND characters are dead, all except Numbuh 274/Chad, Mega Mom, and Destructo Dad.)
And there's an initiation to Kids Next Door Galactic.
Which would unfortunately see the KND leaving home and never returning!
Nigel: Even if we don't see each other again, just promise us one thing, that you'll never grow up, even if you're a hundred years old and don't remember a thing about our times together.
And so, the Kids Next Door head off to space, not knowing anything.
THE END...