What the rat
An alternative to the outdated phrase "What the nasty", because rats are nasty. Rarely used outside of Massachusetts private high schools. A suitable family-friendly substitution for "what the f**k".
Masshole 1: Bro, I saw your girl talking it up with another dude at ultimate frisbee practice.
Masshole 2: Bro, what the rat?
Masshole 1: I feel you bro.
Masshole 2: Bro, what the rat?
Masshole 1: I feel you bro.