Kumbhakaran, or the sleeping giant, was blessed with the capability to sleep for months. Moreover, he could also go on eating the entire world and yet won’t be satisfied. His body was huge.
Although a demon, Kumbhakaran was extremely learned and a great philosopher. Because of his learnings, he knew that all these were sins and never wanted to be indulged in one.
Once Kumbhakaran’s brother, Lord Ravana, needed his sleep, he forgot his principles. It was considered impossible to wake Kumbhakaran.
When war broke out between Ram and Ravana, the latter’s army was skeptical of waking him up. But, Ravana wanted his strong brother to be on his side, for his other brother, Vibhishan, had already betrayed him.