Because chickens didn't exist yet.
He was chicken!
A fried Chicken leg
Because they wanted to be taken to the other side.
To send people to the other side.
Santa Clues. Credit: Curious: The Tourist's Guide
You get a short circut.
A veloci-rapper. What about Stalin? A Tyrant-a-saurus rex.
Stegosaur-rust!
Because he doesn't exist.
At least Pluto exists