The mythical creature known for its ability to regenerate its body is the Hydra from Greek mythology. This multi-headed serpent possesses the unique ability that for each head cut off, two new heads grow back in its place. It symbolizes the challenges of battling evil and chaos, often depicted in the labors of Heracles, where he must ultimately burn its neck to prevent new heads from sprouting. The Hydra represents the theme of confronting overwhelming and resilient evil.