A medium size theropod that is known for cannibalism.
One of the apex predator of Madagascar, Majungasaurus was a fast and powerful dinosaur that was notable for it's penchant for eating it's own kind. While we aren't entirely sure if they hunted each other or scavenged each other, we do know they ate each other. These along with their cousins had rudimentary arms that were pointed backward as this allowed for less wind resistance.
The Majungasaurus appeared in the third episode of Planet Dinosaur, wherein it fought and ate another of it's kind.