Even though they're not a whale, the Killer Whale or Orca is killer, sort of. They are probably the smartest animal in the ocean, using unique techniques and hunting in packs to take down even whales as prey. Orcas also have the most complex social structure of any marine mammal, only behind elephants and primates. Since Orcas are an apex predator, their biggest threats are actually the depletion of prey species, pollution, oil spills and habitat disturbance. They are also considered data deficient, so they are also a bit like the South Island Kokako.