I'm hunger. I'm thirst. Where I bite, I hold till I die, and...

I'm hunger. I'm thirst. Where I bite, I hold till I die, and even after death they must cut out my mouthful from my enemy's body and bury it with me. I can fast a hundred years and not die. I can lie a hundred nights on the ice and not freeze. I can drink a river of blood and not burst. Show me your enemies.