File this under: WOW. In a new trailer for his upcoming movie “Dirty Grandpa“, Zac Efron gets… well… kind of dirty – he smokes crack, he goes wild, and… he strips down to a thong while doing┬áthe Macarena.

Zac Efron - Dirty Grandpa

We’ve known for a while that the kid from High School Musical has turned into a hot, beefy man – but now he’s taking it to a whole new level. “Dirty Grandpa” is a new movie, coming to theaters on January, about a guy who goes with his wild grandpa on a crazy spring break.

If this trailer is any indication – we have a lot to look forward to, at least where it comes to Efron showing his physique…

Watch the full trailer right here: