The clan's roots lay in Xanatos' efforts to create an obedient force of gargoyles, or otherwise similar creatures. Xanatos hired Anton Sevarius to create gargoyle-like creatures using DNA from humans, jungle-cats, and bats. Sevarius injected the DNA of jungle-cats, bats, and electric eels (for energy-compensation) into humans, mutating them into inhuman creatures. These Mutates eventually sought freedom from Xanatos and took refuge in the underground complex that formerly belonged to Cyberbiotics.
Xanatos' next attempt was to clone Goliath, which actually began before the mutate project, resulting in a vengeful and evil gargoyle called Thailog. Thailog teamed up with Demona, and the two hired Sevarius to clone the Manhattan Clan, save for Bronx. During their squabbles for dominance, Demona and Thailog abandoned the clones, whom the mutates took to the Labyrinth, thereby forming the clan.
On Halloween of 1995, Thailog stormed the Labyrinth, injuring Maggie the Cat, and made away with Malibu, Brentwood, Burbank, and Hollywood. Together, they journeyed to Castle Wyvern atop the Eyrie Building to reclaim Delilah. Delilah, spurned both Thailog and Goliath, and all her brothers, save Brentwood, declined to join Thailog and returned to the Labyrinth. It seems that Delilah has developed a strong connection with Malibu.
After the attack, Elisa Maza brought Dr. Sato to act as a medical source for the clan, and to treat Maggie the Cat, who has been injured in the attack by Thailog, and was also pregnant.