10 Messed Up Marvel Villains You Won't Believe Exist

Although originally a Captain America villain, Madcap is today most synonymous with Marvel's Deadpool. The character was created after being subjected to an experimental formula developed by AIM, which meant Madcap was impervious to any and all harm - something he struggled to reconcile with, as the original accident that led to him developing powers resulted in the deaths of his immediate family.

Madcap went a bit loopy afterwards, deciding to torment the citizens of New York and putting many in harm's way. After years spent appearing on-and-off in various comics, he reemerged during the events of Secret Invasion and tried to drive Wade Wilson insane. Madcap then gets absorbed into Wade's own consciousness after they regenerate together, before getting split apart at a later date.

A bitter rivalry would ensue, and in many ways it made perfect sense. Both Deadpool and Madcap are impulsive and indestructible, and it yields some pretty interesting results.

But what's so unsettling about Madcap? His bloodlust for innocents isn't exactly exceptional as far as comics are concerned, and Deadpool's not exactly a moral bastion either, but it's how he returns after one encounter that makes him truly creepy.

After disintegrating himself with a Chitauri weapon, Madcap regenerates inside the body of Deadpool's ally Bob, emerging as a talking tumour who could control his host. It's a pretty gnarly visual, and one fans probably don't want reminding of, so uhh... sorry about that.