The X-Files (1993)

S4E12 Leonard Betts

When a decapitated EMT's body vanishes from the morgue and a lookalike begins working at the same hospital, Mulder suspects this new employee possesses the power to regenerate body parts, including his head. As the investigation unfolds, the agents learn that Betts' body is filled with cancer, allowing him to survive in that state, but he relies on consuming cancerous tumors to maintain his strength.