Scientific name -- Hydra lernaea
Size -- 20,000+ lbs.
Diet -- carnivore, especially cattle and humans

Another of the fierce offspring of Echinda and Typhon, the Hydra was a large serpent with multiple heads and poisonous breath. Killing the Hydra near the city of Lerna in Argolis was the second of Heracles’ twelve tasks. Each time he cut off one of the Hydra’s heads, however, two more grew back. A nephew helped him by cauterizing each wound as a head was lopped off. The last head was immortal, so Heracles buried it under a large rock. Once the beast’s body was dead, Heracles dipped his arrowheads into its blood, giving them extra potency.