Q: If you drop a white hat into the Red Sea, what does it become?
A: Wet.

Q: What do you call a boomerang that won't come back?
A: A stick.

Q: Where do you find giant snails?
A: On the ends of their fingers.
(Giants' nails.)

Q: What travels around the world and stays in a corner?
A: A stamp.

Q: What is white when it's dirty and black when it's clean?
A: A blackboard.

These need to be written.
Q: What do you call a pig with three eyes?
A: A piiig.
Q: What goes Oh, Oh, Oh?
A: Santa Claus walking backwards.

Q: What do elephants have that no other animal has?
A: Baby elephants.

Depending on where you live, students will enjoy this one.
Q: What do you call a hippie's wife?
A: Mississippi.

Q: What did the ocean say to the beach?
A: Nothing, it just waved!