The actor and his "Neighbors" costar Seth Rogen stopped by "The Tonight Show with Jimmy Fallon" on Tuesday night -- where they took part in one of the talk show host's best recurring skits: "Ew!"
The two dressed up as teenage girls, alongside Fallon as Sara, where they showed how to take the perfect selfie and got down to "Turn Down for What."
And while Rogen made for the ugliest lady ever (he didn't even shave!), Efron looked kinda cute ... if you could get past his chest hair and buff muscles.
Zac and Seth aren't the first stars to do drag for Jimmy. In the past, Will Ferrell and Channing Tatum have both donned dresses for the skit, while Lindsay Lohan stopped by for a chat with Sara as well.
How do you think the guys did? Will you be seeing "Neighbors" when it opens this weekend?