Kumbhakarna was a demon and Ravana's younger brother. He belonged to Pulasatya dynasty. He was brother of Kuber. He desired to attain Indrasan. So he started observing severe penance to please lord Brahma. But at the time of demanding Indrasan, goddess Saraswati twisted his tongue. So instead of Indrasan, he spoke Nindrasan. Therefore, he remained asleep all the time. It was difficult to wake him up from deep sleep. So he was known as Kumbhakarna.