The Story Of Kumbhkaran’s Sleep:
Once, brothers Ravana, Kumbhakaran, and Vibhishan were asked what boon they wanted from Brahma. Indra, on the other hand, was well aware of Kumbhakaran’s valor and wit and knew that he would ask from the Indrasan, the Kingdom of Heaven. Fearing this, Indra requested Goddess Saraswati to tie Kumbhakaran’s tongue, which bound Kumbhkaran to ask for the eternal Nindrasan. Brahma granted him the boon of eternal sleep.
Seeing his brother’s plight, Ravana pleaded Brahma to undo the curse. Brahma did undo it, but with a condition. He said that Kumbhakaran would sleep for half a year and will stay awake for another half. Even during the Battle of Lanka, Kumbhakaran was asleep and was walked over by a thousand of elephants in an attempt to wake him up.