Superhuman Stamina – The ability to exert one’s self in an activity indefinitely without becoming tired and/or survive for long periods of time without consumption or water. Superhuman Stamina is also known as Enhanced Stamina, Immense Stamina, Super Energy, Super Stamina, Superhuman Energy and Supernatural Energy.
Kahless and Morath (Star Trek) are brothers that fought for 12 days and nights.
The Wirebound Berserker has unnatural stamina in Creature Collection II. Dark Menagerie.