Imprisoned on Earth so that the Ogdru Jahad would "always have a foothold in the world from which they were banished", Sadu-Hem was discovered by Rasputin in the Gorinium temple at the top of the Arctic circle. Rasputin remained in a trance near the statue until the arrival of Professor Trevor Bruttenholm and the Cavendish exploration party. The newly-awakened Rasputin and Sadu-Hem devoured most of Bruttenholm's exploration party. Bruttenholm was allowed, under heavy psychological compulsion, to return to America, where Rasputin and Sadu-Hem installed themselves below Cavendish Hall. Physically, Sadu-Hem appeared as a gruesome mass of tentacles and snapping claws, with a cluster of eyes and feelers serving as its head. Sadu-Hem was to act as the conduit between Rasputin and the Ogdru Jahad, but was destroyed after Abe Sapien speared Rasputin to death and Liz Sherman set the entire place on fire.
Although Sadu-Hem was apparently destroyed, a small piece of him was discovered in the Cavendish Hall ruins over a decade later. Director Manning had the specimen of fungus preserved in a New Jersey lab, until Sadu-Hem grew strong enough to absorb a human form and escape. Fleeing to Crab Point, Michigan, Sadu-Hem converted an entire town into vicious frog monsters before he was again immolated by Liz Sherman.