"More riddles from the Schoolyard" joke

Q: Why did Tigger stick his head in the toilet?
A: He was looking for Pooh.

Q: What goes, 99-cluck, 99-clunk, 99-clunk?
A: A centipede with a wooden leg.

Q: Why do Aunts, uncles, and cousins depend on you?
A: Because without U they wouldn't exist!