The Ogdru Hem were spawned originally by the Ogdru Jahad during the begining of time, and they assisted their parents during the battle against the Watchers. They lost and the Seven Gods of Chaos were imprisoned in a crystal prison in the heart of the cosmos, while the Hem were slain.
Despite their death, the spawn of the great dragon still continued to exist as spiritis and eventually managed to get physical forms back. Their main mission was to prepare the Earth for the coming of their parents, mainly by spreading destruction and turning humans into Frog Monsters.
Their numbers rose during the apocalypse, but were eventually destroyed by Liz Sherman as she burned the Earth to a crisp.
The Ogdru Hem are based heavily on the works of Lovecraft, resembling cephalopods, worms and crustaceans.