It's like a body but the functioning organs have been replaced by cancerous tumors and growths. It has skin, it walks, but is completely devoid of functionality and reason outside of embracing anything that doesn't fuel the cancer within or spread it to others. You wish it was dead, but normal people mistake it for a real human. It just meanders around promoting its own carcinogenic ends to the unsuspecting.

The worst is that it believes itself to be human - the only true, enlightened human.