Hailing from a small village in Japan, Pensturu was exposed at a young age to large doses of radiation from the Nagasaki bombing which later in life mutated him into his current, salty self. Historians claim the original inspiration for the classic Godzilla series of monster movies was inspired by Pensturu's salt-fueled rage across the Japanese countryside, although such claims are disputed.

Evidence exists of Pensturu fighting during the Finno-Korean Hyperwar where he lead the defense of Manchuria, as well as mercenary work for the African Kangdoms, both showing his incredible combat abilities.

Recent DNA testing has uncovered evidence that Pensturu may be closer in genetic makeup to the common Channel Catfish (Ictalurus punctatus) than to modern humans.