Death of Kumbhakarna at the hands of Rama forms a part of the Yuddha Kanda in the great epic of Ramayana. Kumbhakarna was one of the younger brothers of Ravana who used to stay awake for six months and then sleep for six months. After Ravana was spared in the battle by Rama and was returned to Lanka, Ravana became very angry and was reminded of his brother Kumbhakarna who was the hardest fighter among the Rakshasas. He thus dispatched a host of Rakshasas to wake him up.
Obeying the orders of their Lord, the rakshasa host of Ravana went soon to the cave where Kumbhakarna was sleeping. While sleeping, he looked like a mountain, drunk with sleep, and vast as Hell. At first, the rakshasas placed the feast before Kumbhakarna which included heaps of deer and buffaloes, steaming rice and jars of blood, mountains of food piled up as high as mountain and then started to wake him up, since after awaking from sleep Kumbhakarna would eat up anything that comes before him. Thus, after placing the food before him, they tried their best to wake Kumbhakarna.
At last, the brother of the demon king Ravana woke up and yawned and seeing the food he fell for it and drank and ate. Then the rakshasas told him of the reason for waking him. Kumbhakarna met his brother Ravana and requested him to surrender Sita to Rama and end the war at once. But Ravana insisted on taking revenge from Rama and aroused Kumbhakarna`s patriotic feeling and reminded him of his duty towards his kingdom of Lanka and to his brother.
Thus Kumbhakarna marched towards the battlefield and killed hundreds of monkeys at a stroke. Even Hanuman was unable to resist the demon and Kumbhakarna created havoc in the ground. Kumbhakarna flung a mountain-top at Sugriva and the monkey chief fell down, and he lifted him and carried him away. The monkeys were scattered as they saw their king was captured. But Sugriva roused himself and turned on the demon and wounded him and got away. The battle was joined again, and Lakshmana fought against the rakshasa. Then Rama took up the battle, and wounded the brother of Ravana with many shafts, and shot away an arm of the demon, destroying a hundred monkeys when it fell on them. Then with a second shaft Rama cut away the other arm, and with the help of two keen-edged discs he cut away the two legs of the demon, and at last with a shaft of Indra he struck away his head. Thus, Kumbhakarna fell like a great hill and was crashed down into the sea.