killer whales or orca.. top of the food chain... no natural
predators...
they have been seen hunting everything from baleen whales to
sardines.. and there has been a documented orca which hunts great
whites for the liver which is high in fat..
however, they may toy with their prey, which is a natural behaviour
akin to cats toying with theirs.. but they have shown their
merciful side.. in a documented sighting in Patagonia where they
beach themselves to hunt seals, there was once where they had
enough to eat already and they had stunned too many seals, an orca
was seen helping one back to shore...
they are complex beyond words and are lovely creatures
and there has never been a documented case of a human killed by
them
Lions should do a better job 
