10 Worst Things Harley Quinn Has Done To The Joker
8. Stealing His Cut Off Face - Suicide Squad (Vol. 4) #7
When the Joker's torn off face appeared in the annals of Detective Comics, it seemed a sure sign that the clown had been killed. After all, take literally any other supervillain and cut their face off, and they're as good as murdered - unless they didn't have face skin in the first place, which is actually weirdly common.
Only, the Joker wasn't actually dead. He was in hiding, having asked the Dollmaker to carve off his face for a bit of a laugh. As such, it seems as though he let the GCPD find his carved off face flesh while he was recovering so that it could be in safekeeping for whenever he wanted it back.
Which makes it pretty damn funny that Harley stole the face from the evidence lockers during her time with the Suicide Squad. Because, although we're never shown it, you can guarantee that the Clown Prince of Crime had a bit of a freak out when he found out that his face had been stolen and he might never be able to get it back.