The Nemean Lion was a vicious monster in Greek mythology that lived in Nemea. It was eventually killed by Heracles.
Origin
The lion was usually considered the offspring of Typhon and Echidna, but it was also said to have fallen from the moon, offspring of Zeus and Selene. A third origin has it being born of the Chimera.
Story
The first labor for the hero Heracles, was to rid the Nemean plain of the wild and ferocious beast known as the Nemean Lion. This huge creature was the son of the monsters Typhon (who had 100 heads) and Echidna (half maiden - half serpent), and brother of the Theban Sphinx.
Heracles set out to find the monster, which roamed the land of Argolis. Armed with his bow and arrows and his club (made from an olive tree which he tore up from the roots). Hunting through the Nemean forest trying to find the lions lair, he suddenly stopped in his tracks when he heard a fearsome roar. Heracles turned and saw the huge lion rushing toward him. Quick as a flash Heracles drew his bow and released an arrow, but it failed to harm the lion. As the monster bore down on Heracles he quickly fired another arrow, and again it did no harm, the bronze heads bending as if hitting solid rock; the skin of this creature could not be penetrated by the sharpest of points. The lion pounced, but Heracles smashed his heavy club into the on coming monster, stunning it.
Realizing no weapon could kill this monster he rid himself of them, and fought the monster with his bare hands. Heracles wrapped his great arms around the lions neck and strangled it to death. Once the huge monster was dead, Heracles set about skinning the beast, but the skin was so tough he could neither tear or cut it. Then he tried the enormous claws which were very sharp, this time it penetrated the hide and Heracles removed his trophy. Realizing how impenetrable it was, he threw it over himself as a cloak, pulling the head over his own as a helmet making the pelt into armor which would make him even more powerful. From this time on the skin of the Nemean Lion became one of the attributes of Heracles, as well as the olive club.