Quote:
Originally Posted by
Kent Wang 
Sometimes packs of orca will attack whales. Its most powerful attack is the tail slap. Once, an orca in captivity slapped another orca in the head during a public performance, causing the victim to die of massive hemorrhaging.
Bottlenosed Dolphins are actually quite the predator too. They've been documented killing smaller Harbor Porpoises, ganging up and killing sharks, young dolphins, and occasionally humans by ramming them with the tip of their snout at speed and savaging them with tooth and fin.