Which sea monster was killed by Hercules?

Inquiring minds often wonder about the mythical exploits of ancient heroes. One such tale that piques our curiosity is the legend of Hercules's encounter with a fearsome sea monster. Could you elaborate on which particular sea monster Hercules vanquished in his illustrious career? Was it the ferocious Nemean Lion, which he slew as his first labor? Or perhaps it was the Cretan Bull, which he subdued with his mighty hands? Or did he slay a marine beast, such as the Lernean Hydra, with its many heads and poisonous breath? We are eager to learn more about this mystifying episode in the life of the legendary Hercules.