Cannibals eat their own kind. They are uncultured and destroy life which is the opposite element to death. They wear ornaments and armor made from skulls and bones and also make weapons from bones and that makes them related to death in my opinion.
This creature can be a tough mono death creature. With boneyards and aflatoxin it has more than enough free fodder. It can be used to clear Malignant cells to place your creature.
They can also power vultures and bonewalls. With soul catchers, they can generate a lot of death to make up their cost. They have the same growth potential of Lava Golem and have higher hp and have no cost for their ability. I still think a slight reduction in price would be good as they have weak starting damage. But they are strong in mono death so i need more opinion.
If cost is 3, they could be fractaled and they could eat each others like true cannibals
and gain back quanta with soul catchers for next fractal. Add a couple of bonewalls,boneyards,vultures and aflatoxin you could make a solid deck called Cannibalism lol.