Wolverine of the X-Men can heal from anything. But in Marvel’s Ultimate Universe, its healing factor becomes even stronger … and weirder.

Wolverine is probably the best-known member of the X Men and it has a legendary healing factor. The Canadian mutant has survived everything thrown at him from a steamroller to fights with the Hulk and nuclear blasts. Wolverine is also effectively immortal, surviving the entire Marvel universe to the end. But even with all these feats, the Ultimate Universe version has somehow even more powerful healing factor.

Marvel’s Ultimate Universe was created in 2000 as a way to make iconic Marvel heroes more accessible to new readers. They created new and modernized versions of heroes like Spider-Man and The Avengers. This meant a more streamlined and unified continuity that paved the way for the Marvel Cinematic Universe in later years.

The Ultimate X-Men stripped itself of the supernatural and cosmic elements. So they focused on youth with superpowers who were hated and feared by the rest of the world. In their stories they were as likely to collide dramatically with each other as they were against their villains. The details of Ultimate Wolverine’s past were altered, but he was fundamentally the same character. Although less loyal and more ruthless as a result of Ultimate Marvel’s sharper tone.

Characters in the Ultimate line tended to have powers that were subtly different from their mainline counterparts.

For example, Ultimate Reed Richards has no internal organs, other than its brain, that it can stretch to increase its intelligence. Wolverine’s powers were apparently the same as his main continuity counterpart until a revelation in the Ultimate Wolverine vs. miniseries. The Hulk showed that his limits are beyond what other Wolverines are capable of.

In the Marvel comic Ultimate Wolverine vs. Hulk # 5Logan wakes up in a SHIELD interrogation room where Nick Fury wants to have a face-to-face conversation with him about his battle with the Hulk in previous issues. To prevent Logan from attacking him, Fury takes “face to face” in an extremely literal degree, beheading the mutant and laying his head on a table. Fury assumed that Wolverine’s healing factor would keep him alive with his head removed, but Logan’s physiology surprises him. Wolverine not only stays alive, but also maintains the homeostasis when the head is removed from the body.

Nick Fury speculates that Wolverine’s “healing factor” is not just a healing factor, but a survival mechanism that can change his body in response to his surroundings. This places him beyond Wolverine’s normal abilities as his body can also instinctively respond to necessary stimuli. Where could this lead? Unfortunately, Logan didn’t have many opportunities to test the limits of his strange powers, because Magneto annihilated every last cell in his body in the Ultimatum event, and then the entire Ultimate Universe was destroyed. But at least we were able to see this even crazier form of the healing factor.