Rat

Also known as: Snitch

A "friend" who is chill around you, but if they get asked if you did sum illegal, they will snitch.
They don't care how good you are to them, they will snitch on you either for fun, or they are a pussy and don't wanna lie

Administrator: "Did your friend John pull the fire alarm?"

Rat: *doesn't think twice about it* "Yeah"
Administrator: "Why?"
Rat: "he thought it would be funny"