It is said about... Hydra
" Hydra the nine-headed water serpent, off-spring of Typhoon and chidna, 
Lived deep down in the swamp and killed with the poison-like breath. As one 
Head was cut off by enemies, two new heads re-appeared. It was Hercules to 
Kill Hydra by burning her neck after decapitate each head and trapping her 
Body under a huge rock, Where it's still buried until this day. "