What do you call a train that carries bubblegum?
Chew-chew train! Hee hee!
Listen here, nimrod. It's a play on words, see? "Chew-chew" sounds like "choo-choo," which is the noise a train makes. And bubblegum? Well, you chew it! You're probably the type to eat the gum with the wrapper, you silly goose.