The Hydra is a large, multi-headed serpent monster appearing in Disney's 1997 feature film, Hercules. In the film, Hades summons the Hydra to destroy Hercules, though Hercules manages to defeat it, earning him fame and adoration from the people of Thebes.
The Hydra is a massive, dragon-like reptilian creature with dark purple scaly skin. Its body is rather bulky and it crawls using two legs with four-fingered hands that have claws. It has a long, thin tail and each time one of its heads gets cut off, 3 more grow to replace it. Its number of heads can apparently grow exponentially up to at least 18 in Hercules, though in Kingdom Hearts II its maximum is seven and in the read-along story it was 30. All of the Hydra’s heads are identical to each other, each resembles a cross between a snake's and a monkey's, a large mouth filled with white fangs and long snake-like tongue, orange eyes with slit pupils, and spikes lining the top of their heads down the length of their long, serpentine necks.
The Hydra is the first obstacle sent by Hades to kill Hercules. Lured to a canyon outside of Thebes, Hercules unknowingly releases the Hydra from a cave after rescuing two children (Pain and Panic in disguise) from under a boulder. The two thank Hercules before running off to Hades and leaving the hero to feel a false sense of accomplishment, oblivious to the unintended consequences that would come of his actions.
Moments later, Phil joined Hercules in the canyon, and they became aware of a hissing sound. The Hydra surprises Hercules by approaching him from the inside the cave, forcing the hero into combat. The monster lunges at Hercules, but he dodges the serpent and keeps her at bay, until the monster strikes and knocks him back. Realizing he lost his sword, Hercules defenestrates the beast by hurling a boulder at it, only for the Hydra to crush it into stones with her teeth and laughs at the hero's clumsy attempts. When the Hydra next strikes, Hercules grabs the monster's teeth, struggling as he is pushed back by the creature. He slams its head into the ground, giving him time to grab his sword. However, the Hydra lashed out with her tongue and caught Hercules by his ankle. She flips him into the air, and swallows him whole. Satisfied, the Hydra let out a loud burp and licked her lips. The Hydra smiled until a sick look spread across her face. While in the monster's throat, Hercules cuts his way out by decapitation with his sword from the inside-out. The huge head tore from the body and landed in the middle of the crowd. Standing next to the Hydra's headless steaming carcass, the hero is again lured into a false sense of security before, as Hades expects to happen.
An eerie hiss wheezed from the Hydra's wound, as three separate writhing heads oozed from the wound. It chases down Hercules around the canyon until Pegasus picks up Hercules just as he was about to be bitten. Together they soared into the sky as the hero fights back, to little avail. With each head Hercules slices off, three more grow in its place. Frantically, Hercules chopped at the hideous monster, continuing until he is surrounded by a hissing swarm of heads. Suddenly one head struck Hercules, knocking him off Pegasus, and he fell into the living jungle of Hydra necks, as the snarling heads gang up to attack him. Hercules barely makes it through until he is flung into the air, and is pinned a cliff with the sharp talons of the Hydra's foot. All of the monster's heads lick their slimy lips, ready for the final attack, as it is about to finish the young hero off. As all heads lunged at once, Hercules quickly punches the cliff, which causes an avalanche of rocks to fall. The Hydra freezes as all of its heads look up in fear, then the Hydra is crushed and buried in a mountain of rocks, ultimately defeating the Hydra for good.
All that is seen of the Hydra after the rockslide is its claw (where Hercules was held). Everyone in the crowd, including Pegasus, Phil, Meg and Hades thinks that Hercules had died with it; however, all a sudden the Hydra's claw started moving. The crowd was afraid at first, thinking the beast is still alive. But once the claw opened, it is revealed to be none other then Hercules who survived, and everyone started cheering for Hercules as the light shine on a new hero.
During the song Zero to Hero, everyone is watching a play featuring Hercules bravely fighting the Hydra in battle. Unlike the actual battle, the play shows Hercules fighting three headed Hydra, with Phil behind him and not running away.
In "Hercules and the Long Nightmare", Phantasos creates a discomforting quilt to make everyone have bad or scary dreams and frame his brother, Morpheus. Hercules had a dream when his adult self visits Zeus and Hera on Mount Olympus, and a three-headed Hydra appeared. One Hydra head grabs Hercules by his cape, dangling him while the other two snapped at him. Phil had a dream until it was interrupted by witnessing Herc's dream, seeing Herc attacked by the Hydra but the hero couldn't fight back because he dropped his sword. When talking of the scary dream, Phil pointed out it was he skipped sword practice to watch cheerleader tryouts at school. The next night, Hercules dreamed of his teenage self grabbed by the Hydra. He screams for help before the Hydra swallowed whole. The Hydra's three heads turn into faces of Phantasos. Hercules continues having the dream, saying he couldn't get out and was stuck in its pancreas, before waking up. When Morpheus asks for Hercules's help, Hercules mentioned how the Hydra was "as scary as they come". Both Hercules and Phil once again face Phantasos, who transforms into the Hydra. Proclaiming he's no longer afraid and Phil's advice that it's just a dream, Hercules bravely tricks the monster, tying the Hydra's necks, then he grabs the tail, spins it around, and throws the monster into a hole before Phantasos turns into Typhon, the father of all monsters. After stopping Phantasos, Hercules told Morpheus that because of the dreams, he wouldn't be afraid if he ever faced a real Hydra, that tackling it in his dreams made it less frightening.
The Hydra appears briefly in the Philoctetes' Hero-Training Program advertisement at the end of the episode "Salute To Sports". It had three heads and was facing Donald Duck in the canyon outside of Thebes.
Hades sent the Hydra to destroy the Olympus Coliseum and kill Hercules. Hercules had to fight it in the Coliseum and believed he had knock it out. However, it was in fact playing dead and started to destroy the Coliseum. Sora then fought it with his friends and beheaded it until it could no longer grow heads. However, the aftermath of the battle was rather unfavorable—the Coliseum was destroyed and Hercules lost his hero's glow, making him later fall prey to the plans of Hades.
The Hydra is based on the Lernaean Hydra, a serpent-like water monster of Greek mythology. It originally had nine heads that would replace each other in the same manner as the Hydra in Hercules, and was killed by Hercules as the second part of his Twelve Labors after The Nemean Lion.
When the Hydra was seen as a baby being fed by Echidna, it already has three heads even though it started with only one.
As stated in the myth, Hercules slew the Hydra by slicing off its heads, then using a torch to cauterize the stumps left.
The Hydra is rendered in CGI, unlike the rest of the movie which is in hand-drawn animation. This was done as it would have been incredibly difficult to draw each head individually.
The boulder that Hercules threw at the Hydra was shaped like a blaster.
When the Hydra bit the boulder in half, its laugh was the grunting of a hippopotamus.
The Hydra is a rare instance of blood and gore shown onscreen in a Disney movie, as it visibly bleeds green blood after its heads are cut off.
In Once Upon a Time, the Hydra does not appear. However, when Hercules tells his twelve labors to a teenage Snow-White, one of his medals represent the creature.
According to the Disney Read-Along story, junior novelization, and art book of Hercules, the Hydra grew a total of 30 heads. They also identified the Hydra, with the terms "she" and "her", as a female creature.
However, the math shows if Hercules removed 1 head and 3 more were added up to 14 times, the closest result would be 29. The heads cannot be an even number.