The real monster here is guilt. Or maybe the Werewolf.

Spider-Man's kryptonite is basically guilt. Peter David's kryptonite might be jokey titles. Like today's book! From 2006, Marvel Adventures: Spider-Man #17, "Hair of the Dog that Bit Ya" Written by Peter David, pencils by Mike Norton, inks by Norman Lee.

After a homecoming rally he didn't want to go to, glorifying his bully Flash Thompson; Peter Parker sees Flash take a dare to go into the allegedly-haunted old Russell house...where he's attacked by a werewolf! The Werewolf By Night, to be exact, since "by night" I guess separates him from all the other werewolves...Spidey gets Flash to the doctor, Dr. Strange to be exact; who says he can cure him with some of the werewolf's fur, if done before the sunrise. Even though he's been driven by guilt almost constantly since becoming Spider-Man, Pete has a hard time finding the motivation to give a crap what happens to Flash.

Nonetheless, Spider-Man ends up fighting the Werewolf, who was wearing the remains of chains and restraints: Jack had secured himself, but broken loose, and I wouldn't be surprised if the Werewolf got out because Flash got in there and agitated it. With the sunrise, the Werewolf reverts back to Jack; and Spidey is kicking himself for letting down Flash, who didn't deserve to become a werewolf. (Didn't he, though? A little?) Getting a lump of fur back to Strange, a dejected Spidey feels like he didn't try his best and failed; but Strange tells him he needed the fur before the next Romanian sunset, since that was where the curse originated, and still had like fourteen hours. Still, lesson learned for Spidey, who resolves if someone needs his help, he will always do his best. Even if it's for a total tool...