Hydra

The Hydra is a massive monster, that served Hades in the Disney vs. Non-Disney Villains war, only appearing in the final battle. Queen Narissa also adopted the monster's form to battle Hades and Maleficent in the finale of the Disney Villains War.

It first appeared as one of Hades' many monsters in the Disney animated film Hercules.

Pre War: Eating Monsters for Dinner
Prior to the events of the war, when the titan, Chronos, confronts his son, Hades, he takes his servants into the battle by attacking his son. However, Hades managed to took control of her by blasting one of them with his own powers while calling Hydra to his aid to devour some of the monsters of Chronos. This was the only scene of Hydra during the fight on Bald Mountain.

The Battle Of France
During the final events of the war, Hades summons again his pet to cause destruction and chaos to Paris. While many troops were unable to kill her, the Griffin chopped one of her heads, only to his horror that instead it give her multiple heads. While this battle was happening, the dinosaur, Sharptooth, came to challenge her, but instead of attacking her personally, Sharptooth banged his head into a rocky mountain, which caused it's giants rocks to fall and bury the serpent under from the rocks, much to Hades fury.

Killing An Intruder
When the thief, Gazeem, entered the Underworld to steal some magical artifacts for Jafar, he was encountered by the queen of the Underoworld, Narissa. After seeing him, Narissa took the form of Hydra and eat him alive, leaving an angry Jafar to leave this place at once, while Narissa returned to her normal form.

Serpents Fight
After Jafar infinitrate the Underworld and transform himself into a Giant Cobra form, Hades took the form of Hydra to challenge him. However, Jafar slayed her head, leaving her body, collapsing to the floor, much to Jafar's laughter. It was later revealed that Hydra (aka Hades) survived the attack and returned to his normal god form.

Dragon Vs Monster
At the final events of the war, Queen Narissa fought the mistress of all evil, Maleficent, to defend the Underworld from her enemies. Seeing that, Maleficent quickly transformated into her dragon form to fight her. But it was no worth for Maleficent to kill her easily, because that everytime he chopped her, multiple heads come over to her body. After the dark fairy was weakened by her powers, Narissa take her advantage by injuring her. However, just as she was attacking Maleficent, the dragon banged herself into a cliff, she was standing, to the monster burying her alive and taking Maleficent with, much to the horrors of their allies.

Fight With The Hobgoblin
During the events of the war, the Hydra was under the control of Nathaniel, along with a troll he found on his way to Kingpin's flat, on purpose to free his queen, Narissa, who was imprisoned after an encounter with Whiplash. At their arrival they confront Hobgoblin, a dangerous mutant creature. After the troll fails to deal with him, it was time for the Hydra to attack the goblin. At first his head got sliced from it's body by his weapons, only to his shock that it repaired himself by coming over many heads from her body. In a final stand, the Hydra take it final strike to it's enemy, however Hobgoblin uses his fire bombs to destroy a cliff that Hydra was under from it, burying it alive from the big boulders.