M R snakes.
M A no snakes.
O S M R snakes.
CDBDI's?
O S! M R snakes!
AAAAAAAAAA!

-My dad told me this one years and years ago. I'd almost forgotten it until tonight. Here's another one:

Mairzy dotes and dozy dotes and liddlamszy divy.

-The answer: Mares eat oats and does eat oats and little lambs eat ivy.

And an old knock-knock joke:
Knock, knock.
Who's there?
Banana.
Banana who?
Knock, knock.
Who's there?
Banana.
Banana who?
Knock, knock.
Who's there?
Banana.
Banana who?
Knock, knock.
Who's there?
Orange.
Orange who?
Orange you glad I didn't say banana again?

Hope you had fun!