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)
Cannibalism was a cultural practice of the Valethske, ordinarily as a form of execution, but occasionally occurred during feeding frenzies. (PROSE: Superior Beings)
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)