Traditionally it was to slay the Nemean Lion, which had a hide no steel or stone could penetrate.
The Nemean lion.
Hercules brought Cerberus, the three-headed dog, to Eurystheus, the king of Tiryns, as part of his twelfth and final labor. Eurystheus had tasked Hercules with capturing Cerberus from the Underworld and bringing him to the surface without using weapons. This labor demonstrated Hercules' strength and bravery, as well as his ability to confront death itself. After presenting Cerberus, Eurystheus was so terrified that he hid in a large jar.
Hercules killed the Nemean lion as part of his Twelve Labors assigned to him by King Eurystheus. The Nemean lion was a fierce monster terrorizing the region of Nemea, and Hercules was tasked with slaying it as his first labor.
His punishment for the slaying of his wife and children was to labor for his rival Eurystheus. These became the Twelve Labors.
A bull that was said to breathe fire. The Cretan Bull was the property of King Minos, and this was the seventh labor given to Hercules by King Eurystheus.
As punishment for killing his family in a fit of madness, Hercules was required to perform a series of tasks known as the "Twelve Labors of Hercules." These tasks were assigned by King Eurystheus and included challenges such as slaying the Nemean Lion, capturing the Golden Hind of Artemis, and retrieving the Erymanthian Boar. Each labor tested Hercules' immense physical strength, bravery, and cleverness. Completing these tasks ultimately led to his redemption and immortality.
The Nemean lion.
Hercules was instructed to perform twelve labors as a form of penance for killing his wife and children in a fit of madness, which had been caused by the goddess Hera. These labors, assigned by King Eurystheus, included tasks such as slaying the Nemean Lion, capturing the Golden Hind of Artemis, and retrieving the Cerberus from the Underworld. Completing these challenges was meant to purify him and restore his honor. Each labor tested his strength, courage, and ingenuity.
The Nemean Lion.
He wears the Nemean lion's skin.
Hercules' 3rd labor was to find the Ceryneis Hind. He did it for King Eurysetheus.
After the big Lion of Nemea, which Hercules killed as his first labor.