Leo is latin for “Lion.” It is  associated with the Lion of Nemea in Greek mythology, which terrrorized the town of Nemea. Heracles, as part of his seven labors, was sent to kill the beast. The lion had invulnerable skin, which meant his arrows were completely useless. It is said that Heracles went into the lion’s lair and choked it to death. Heracles went on to wear it’s skin as body armor. One of Leo’s stars, the eta Leonis, is 2,100 light years away.

All information from http://www.topastronomer.com/StarCharts/Constellations/Leo.php