Onomatopoeia jokes

What do you call a train that carries bubblegum?

Chew-chew train! Hee hee!

What do you call a freight train with bubble gum?

A chew-chew train!

Knock knock.

Who's there?

Milk man.

Milkman who?

Milk poooooooooooooooop peeeeeeeeeeeeeeeeep man!