Hercules

Hercules, or Heracles, was a demigod and a legendary Greek hero. Among other high deeds, he defeated the Hydra. (PROSE: Introduction and links, Mythical Monsters)

Origins
Heracles was a son of Zeus, which made him a sibling of Apollo, Athena, Artemis, Castor and Pollux, Hermes, Hebe, Minos and Persephone. Due to his demigod parentage, (PROSE: Deadly Reunion) he had superhuman strength. (PROSE: Mythical Monsters)

Twelve Labours
Hercules was set twelve tasks by a Greek king. Among them was killing the Hydra, a "terrible serpent with nine ferocious heads", who regrew two new heads whenever Hercules cut one off. (PROSE: Mythical Monsters) Hera sent the Carcinus, a giant, malevolent crab, to try and distract Hercules from his battle with the Hydra, but he managed to defeat it as well. (PROSE: Introduction and links) Hercules managed to defeat the Hydra despite its regenrative ability by having a servant place a burning brand on the wounds, preventing new heads from growing. Though the Hydra's ninth and final head was indestructible, he cut it off too before burying it underneath a boulder. (PROSE: Mythical Monsters)

Another task saw Heracles kill the "nigh-invulnerable" Nemean Lion, whose pelt he subsequently wore as armour. (PROSE: Introduction and links) In a later task, Hercules was asked to capture the "great bull of the King of Minos", the Minotaur. Hercules somehow succeeded in making his way through the Labyrinth, bringing the Minotaur back in chains. Finally, for his last Labour, he was asked to travel to the land of the dead and capture the three-headed hound Cerberus. He succeeded and brought him before the Greek king setting him the tasks. Terrified, the king immediately asked Hercules to put the dog back where he'd found it. (PROSE: Mythical Monsters)

Undated events
On the planet Augea, both the Tenth Doctor and Hercules were involved with twelve quests, including cleaning the Augean stables and cleaning up after Cerberus. (PROSE: Sting of the Zygons)

According to Eos, at some point, Heracles threw two people directly "into the heavens". (PROSE: Wandering Stars)

Heracles once loosed a poisoned arrow at the kind, harmless Centaur Chiron by mistake. Though Chiron was immortal, he could not rid himself of the pain, and the Gods took pity on the Centaur, making him mortal so that his soul could ascend to the heavens to join them. (PROSE: Mythical Monsters)

Legacy
Hercules was remembered in the legends of the Greeks and Romans, alongside other heroes who had fought monsters in ancient history, such as Perseus. (PROSE: Mythical Monsters) Legend claimed that the constellations Leo, Cancer and Sagittarius were created to commemorate three of the creatures slain by Heracles, namely the Nemean Lion, the Carcinus, and Chiron. (PROSE: Introduction and links) As early as during the Trojan War, Priam, commenting on Paris' pride in having captured a Greek soldier, said, "One pathetic prisoner and he thinks he's Hercules." (TV: The Myth Makers)

Lysippos sculpted a bronze statue of Hercules which was "last seen before Constantinople fell". It was one of the rare works of art hoarded by Scaroth. (PROSE: City of Death)

Behind the scenes

 * Hercules and Heracles are the standard anglicised forms of the Roman and Greek names for the figure, respectively. However, various DWU sources have used the name "Hercules" in sources which otherwise use Greek names for the Olympian pantheons.
 * Contrary to that which is portrayed in Mythical Monsters, the original myths' Hercules never encountered the Minotaur; the "great bull" he captured was the, who actually sired the Minotaur.
 * An was created by Disney in 1997, in which Wayne Knight had a minor role.
 * The Table of Contents of Myths & Legends noted that the story The Multi-Faceted War was inspired by the myth of Hercules and the Hydra.