On the main side Heracle´s fight against the Nemean lion is illustrated. Heracles takes the animal´s front paw and attempts to wind around its neck. The lion leans on Heracle´s knee and has its front claw around his shoulder. On the left and right side, two spectators observe the fight holding javelins in their hands.
On the shoulder of the vessel two athletes box with their fists. On the right and on the left side two referees are watching the fight.
Killing the Nemean lion was the first of twelve tasks, set up by the king of Argos, Eurestheus, and which Heracles accomplished with great success. The Nemean lion was a monster, who killed humans and animals. Heracles slayed the monster by hitting on its head with a club and struggling it with his own hands. Afterwards, the hero cut off his pelt and made a cloak thereof, which he always wore for his defence. In this way, the cloak became the characteristic symbol for Heracle´s acknowledgment.