Kumbhakarna looks much like a Rakshasa, except he is twice the size. He is also much bulkier than a normal Rakshasa. This has led to speculation that he is merely a Rakshasa modified to be strong and intelligent. This is not suggested to him, however.
Psychology
Kumbhakarna is both adept in the skills of battle and technology, unlike most Korgrath. Because of this, he is widely sought in the Daemoniverse, but his loyalty to Ravana means he works for nobody else.
Equipment
Kumbhakarna carries a specially made Blueblade that is more powerful than the standard of its type.