Legends abound regarding Hercules (Herakles to the Greeks). One of the most important involves a great monster - the Nemean Lion - who was roaming the Nemean Plain, in the land of Argolis, terrorizing people at will. Heracles (Hercules) was sent to kill the lion. He soon learned it was a nigh-to-impossible task.
With his club (made from an olive tree which he'd torn up by its roots), bow and arrow and (according to some classical accounts) a bronze sword, Heracles searched for the great beast. Searching the Nemean forest, he found nothing. Then - Heracles heard a fearsome roar, and the lion was upon him. Instantly releasing an arrow, Heracles could not kill the monster with a weapon. Nothing could penetrate his tough skin. Heracles would have to use his bare hands.
With his powerful arms and hands, Heracles wrapped his personal weapons around the lion's neck - and strangled it. Unable to skin his prey, after its death, Heracles used the lion's own extremely sharp claws to fashion a cloak which could also serve as impenetrable armor. Pulling the dead lion's head over his own, Heracles then had a helmet to protect himself from harm.
From that time forward, the skin of the Nemean Lion and the olivewood club became attributes of the great hero Heracles (Hercules).
In this image, he is fighting the lion. It is a detail from The Twelve Labors Roman mosaic in Llíria (Valencia, Spain). An unknown artist made the work with limestone, likely in the first half of the 3rd century. It is owned today by Museo Arqueológico Nacional - the National Archaeological Museum of Spain.
Click on the image for a better view.