What joke will a fool become when he grows up?

A joke between a fool and a wise man. The wise man asks a fool a question, and the fool gives him a dollar if he can't answer it. If the wise man can't answer, give the fool a hundred dollars. The wise man asked the fool, "What is meow?" I don't know. "Fool, it's a cat!" The fool gave the wise man a dollar. It's time for the fool to ask a question: "What are three legs and six eyes?" I don't know. The wise man gave the fool a hundred dollars. "What is that?" "I don't know, I'll give you a piece," said the fool.