Scientists from the University of Amsterdam have discovered a population of giant, near ape-size chimpanzees in the Congo. Long rumored to exist, they are referred to by local hunters as lion-eating chimps. And while the scientists could not confirm the lion-eating, they did see a band of the chimps eating a leopard.
The chimps are particularly aggressive, and they use tools to smash their food. Named Bili apes, after a nearby village, they're unusual enough that scientists have proposed creating a new chimp sub-species. (More Bili apes stories.)