Ghatotkacha is an important character in the Mahabharata. His name comes from his head, which was hairless (utkacha) and shaped like a ghatam. Ghatotkacha was the son of the Bhima and the Hidimba. His maternal parentage made him half-Rakshasa and gave him many magical powers such as the ability to fly, to increase or decrease his size and to become invisible. He was an important fighter from the Pandava side in the Kurukshetra war.
In the Mahabharata, Ghatotkacha was summoned by Bhima to fight on the Pandava side in the Kurukshetra battle. Invoking his magical powers, he wrought great havoc in the Kaurava army. In particular, after the death of Jayadratha on the fourteenth day of battle, when the battle continued on past sunset, his powers were at their most effective.
At this point in the battle, the Kaurava leader Duryodhana appealed to Karna, to kill Ghatotkacha as the whole Kaurava army was coming close to annihilation due to Ghatotkacha's attacks. Karna possessed a divine weapon called the Vasavi Shakti, granted by the god Indra. Only able to use it once, Karna had been saving it for his battle with his rival, Arjuna. Unable to refuse Duryodhana, Karna discharged the weapon against Ghatotkacha, killing him. It is said that when Ghatotkacha realized that he was going to die, that he assumed a gigantic size. When the huge body fell, it crushed one akshauhini of the Kaurava army. After his death Krishna smiled as Karna no longer had Vasavi Sakthi to use against Arjuna.