User blog comment:Lord Loss/Monster Hunter Theory... Blog/@comment-5043481-20121031224426/@comment-4212769-20121101154039

It can. It's possible that Fatalis could eat even rotten meat. It could be a rather lazy hunter that's why it found a way to eat even rotten parts. It could also have found a way to keep decomposers from the meat that it is longer edible.

It could also be just eating parts of it leaving the rest for other monsters to feed off. It doesn't need to eat the whole thing.