Lernaean Hydra
When he returned on the thirtieth day, carrying the carcass of the lion on his shoulders, King Eurystheus was amazed and terrified. Eurystheus forbade him ever again to enter the city; in the future, he was to display the fruits of his labours outside the city gates. Eurystheus warned him that the tasks set for him would become increasingly difficult. He then sent Heracles off to complete his next quest, which was to destroy the Lernaean Hydra.