The Hydra is a large multi-headed monster that Hades summoned to destroy Hercules. It's head was cut off by Hercules but three more took it's place with every decapitation. Eventually Hercules manages to kill it by causing a mountain to crash on top of it, thus earning him fame and adoration from the people of Thebes. in the spongebob verson of the film, the Hydra will also have a more major role, where, outside of it's ovivous first battle, it will also be one of the monsters allied with the Cyclops to attack the town, others being Tzekel Kan's Stone Jaguar and the reserected Red Death Dragon. after it's defeat, Mirage will reserect the monster as one of her own pet monsters of the villain leage, and even aide as an addisional ally to the monsters of Dark Cynder (which will soon be the villain leage nightmare patoon).