Actor Zac Efron, who sported an incredibly sexy and natural mustache, decided to slut it up by dressing as a cop from “Reno 911!” who wears a short shorts version of his friendly officer uniform to attend the Halloween party of the year for hot young Hollywood on Sunday night (October 30)- see more pictures below.

Is Zac trying to tell us something with that ridiculous costume? Or is it all fun and games?

Is He Gay? Zac Efron Caught Holding Hands With a Guy

The 24 year-old posed with fellow actresses, Aly Michalka and AJ Michalka, in a party also attended by Julia Robert’s niece, Emma Roberts dressed as a sexy bunny, and allegedly hosted by the one and only Miley Cyrus. I have absolutely no idea what Miley’s idea for a costume exactly was (zombie kitten?), but she looks fantastic (see pic below).

Trick or treat? Happy Belated Halloween!

Zac Efron, Emma Roberts & Miley Cyrus Halloween Bash Pictures

[images: Aly & Aj Michalka/Twitter]