We've heard of celebs receiving some strange gifts from fans, but Zac Efron might have gotten the craziest!

Appearing with his 'That Awkward Moment' co-star Miles Teller on last night's (Feb. 3) 'Conan,' Zac confirmed that one of his fans sent him a piece of her (or his) own skin. Ewww, gross. So gross that Zac didn't even mention it to host Conan O'Brien himself. Miles spilled it instead.

"I was like, 'Zac, what's the craziest thing a fan has sent you?'" Teller remembered. "He was like, 'Oh, I had a fan send me a piece of their skin.'"

Efron was practically speechless from that point, trying to not make a big deal of it. Maybe he was concerned about potentially triggering negative reactions from disturbed fans -- but he did admit that he was weirded out about it. Also, he loves his fans!

Efron and Teller also dished on experiences with Viagra and read a funny text from their missing co-star Michael B. Jordan, who was snowbound back east following the Super Bowl. Watch the clip below!

Zac Efron + Miles Teller Talk Fan Gifts, Viagra on 'Conan'