Cannibalism

Cannibalism was the act of eating members of one's own species. While this was sometimes a choice or a lifestyle, for some species this was a natural activity. Mayflies practiced sibling cannibalism, leaving only the strongest of them left in the end. (TV: Reset)

The Brynblaidd cannibals killed and ate wanderers near their village every ten years. (TV: Countrycide)

At some point in Tennessee, there was a case of cannibalism, though the culprit claimed not to remember the crimes. (PROSE: The Juror's Story)

Alan Jackson at first thought the Slitheen were cannibals when he saw their skin suits lying around. (TV: The Lost Boy)