Actually, Mangle did the bite of 87 on an unsuspecting Jeremy Fitzgerald, Jeremy was ok however and continued living, you can "🤓" me if you want I guess
First of all 🤓 because you asked for it. Second of all if we use patterns we can tell that dread bear did the bite of 83 making a bear be more obvious for doing the bite of 83 which it also can’t be toy Freddy because toy Freddy is… toy Freddy so that leaves withered Freddy and withered gold Freddy but I’m sure Cassidy just does not like William Afton so I’m convinced withered Freddy did it. More evidence is in the fnaf wiki where they discus the 3 main suspects. First being mangle and then withered foxy but you also get withered Freddy. In conclusion I think that withered Freddy did the bite of 87 but I could still be wrong, trust your own opinions (okay this paragraph was longer than expecting)