W - is for Wolverine

Quote from Wikipedia that substantiates my point:

Depictions of the speed and extent of injury to which Wolverine can heal vary. Originally, this was portrayed as accelerated healing of minor wounds, but writers have steadily increased this ability over the years. After several years, Wolverine's healing factor was depicted as healing severe wounds within a matter of days or hours. Other writers went on to increase Wolverine's healing factor to the point that it could fully regenerate nearly any damaged or destroyed bodily tissues within seconds. Among the more extreme depictions of Wolverine's healing factor include fully healing after being caught near the center of an atomic explosion and the total regeneration of his soft body tissue, within a matter of minutes, after having it incinerated from his skeleton. It has been stated in the Xavier Protocols, a series of profiles created by Xavier that lists the strengths and weaknesses of the X-Men, that Wolverine's healing factor is increased to "incredible levels" and theorizes that the only way to stop him is to decapitate him and remove his head from the vicinity of his body.