Mr. Immortal is a mutant with the power of immortality, which allows his body to regenerate from any injury, including ones that would kill ordinary humans. Although injuries that are sufficiently traumatic appear to kill him at least initially, his regenerative power causes him to return to life in anywhere from ten minutes to seconds. This rapid healing manifests itself only in response to nominally fatal injuries: when non-fatally injured, he heals at a normal human rate, though such injuries tend to rapidly heal the next time he dies. This ability seems to be unconscious, since he has tried to commit suicide on numerous occasions, only to walk away unscathed afterwards. He has recovered from being shot, suffocated, stabbed, drowned, crushed, starved, dehydrated, exploded, poisoned, decapitated, irradiated, and incinerated. Upon revival, he is often extremely enraged, due to the pain of death. During Dinah Soar's tenure as his teammate, she could utter a vocalization, inaudible to humans, that could bring him out of this state, which Flatman speculated is hypersonic in nature. Mr. Immortal's body does not age.