Mutagenic corpse
Eating flesh from a mutagenic corpse grants a living character a random mutation and makes an undead character rot. If the flesh is rotten, the likelihood of it being a bad mutation is much higher. Eating mutagenic flesh provides no nutrition.
If you feel like gambling with mutations, you can try scarfing down every mutagenic corpse-leaving monster you cross paths with (sky beasts and ugly things are the more common examples). This is quite risky, as some mutations can easily doom a promising character. Alternatively, you can use mutagenic corpses as makeshift potions of cure mutation if you've accumulated several bad mutations; it's still risky, but you might end up better off than you were.
History
In 0.12, Fulsome Distillation was removed, meaning players could no longer use these corpses to create free potions of mutation.
