Echidna

Half a fair-cheeked bright-eyed nymph, half a monstrous serpent, speckled and terrible — dwelling in a hollow cave under the earth, far from gods and men, among the Arimoi. With Typhon she bore the great brood of heroic-age monsters the heroes would later hunt down one by one: Orthus the two-headed hound of Geryon, brazen-voiced Cerberus at the gate of Hades, the Lernaean Hydra, and the fire-breathing Chimaera. The Apollodoran tradition extends the same parentage to the Nemean Lion.