Cannibalism is the act of consuming another individual of the same species as food. Cannibalism is a common ecological interaction in the animal kingdom and has been recorded in more than 1,500 species. Human cannibalism is well-documented, both in ancient and in recent times.
I know since it won a bunch of Oscars people like to call it a thriller but one character eats people, and another skins them alive and wears their skin as an outfit. I am going to go with a horror film for this one.