Rancor

The Rancor is a ferocious creature created to destroy Jabba the Hutt's prisoners. When Jabba the Hunt opened a trapdoor beneath Luke's feet, he was sent down to the Rancor Pit, where the Rancor was freed to kill him. However, Luke makes the cage bars fall down on Rancor's head, killing him.

In the extended cut of Through the Trapdoor, William Missionima found a dead Rancor in his tunnel.