Your body has been invaded by an ultra-virulent, super-strong form of otherworldly cancer. Rather than simply killing you, the cancerous cells begin to take over the function of your normal cells, but causing you to grow enormous, bulbous, meaty tumours all over. (Think: Akira.)
Mutations: ugly, deformed, badly deformed, grotesque, ponderous, sores, chemical imbalance, thin-skinned, disease resistant, strong, disease immune, parasite resistant, parasite immune, fast healer, very fast healer, regeneration
Post-threshold: amorphous body, metastasization, tumourous brood, terrifying
Metastasization: By touching an organic lifeform with your bare hand, you can send tendrils of your own cancerous infection into the organism, tying them to you with thick, ropy, fibrous growths and causing increasingly large damage over time. This simultaneously feeds you as you essentially convert their body into yours. While this is happening you can only use one hand. If you move, you rip out the growths from your own flesh, causing damage to your arm, and stopping the effect. If you kill an enemy this way its body is completely absorbed, restoring you to perfect health. (Only works on large, living lifeforms, so zombies, squirrels, etc. aren’t affected.)
Tumorous brood: At the cost of hunger, you can grow small, toddler-sized, semi-sentient tumours from your own flesh. They will follow you around and attack your enemies, act as distractions, and so on. They can’t feed and will eventually die of starvation. Their bodies can be butchered to produce meat, so you can eat them and get back the nutrition you lost.