Echidna's Chidren are extremely powerfull monsters of the notorious character, Echidna. Based on the actual creatures from the Ancient Greek Mythology, the Monsters differ in size, powers and abilities. Origined from the television series, "Hercules", the Monsters of Echidna appear occasionally in the villains tournaments.
Hydra appears, prior to the events of the first war, as one of the pet sidekicks of Hades. When he is confronted by Chronos and his servants, Hades sics Hydra upon the servants, devouring them in a flash.
Loyal Pets of Hades
After the Underworld is reclaimed by Hades, Cerberus makes a brief appearance, as the God of the Underworld feeds him with the latest prey he found along his way. Later, Hades watches the events in the mortal world. Specifically, he witness the battle between Frollo's forces against Ruber's forces. During the battle, he unleashes the Hydra in Paris, which it manages to frighten both armies. After the Griffin chops his head, the Hydra grows more heads to the chopped area, while it was ready to kill the flying monster. However, Sharptooth, a monster in the service of Eris, arrives and crushes a giant boulder upon the Hydra, causing it's debris to fall upon the creature, killing it, much to Hades' fury.
Ladon (A small piggie-like creature, who has the psychology of a newborn baby)
Gegenius (A multi-armed monster and an exclusive monster in the Hercules universe, Gegenius serves as one of the primary enforcers of the whole team)
Echidna's Cyclops (A human sized monster, featured as one of the ferocious , yet jolly at times, creatures of Echidna. Though, there is an analogue of the same character, that serves the Titans, this Cyclops' character appears only in the television series of Hercules, and not in the actual movie itself, thus it is a different breed of the original character)
Chimera (A monstrous beast, serving under Echidna)