Heracles was tasked with killing the hydra and for this feat, he brought along his nephew, Iolaus. They covered their noses mouths to protect themselves from the deadly fumes of the beast and attacked. Heracles cut off one of the monster's heads, but then two head grew back and took its place. He cut off two more heads, and four more grew back. Thankfully, Iolaus figured out he could use a burning torch to seal the neck stumps when Heracles cut off one of the heads so they couldn’t grow back. Heracles put an end to the hydra when he cut off its main head and buried it under a large rock.