4. Orcas were once called whale killers, but the name has somehow been transposed to killer whales. Orcas are called killers not because of their behavior toward humans, but because of the way they treat other ocean creatures. They are fierce, quick, and intelligent predators with huge appetites. Orcas will hunt fish, squid, penguins, seals, whales, and other dolphins. Nonetheless, there are no records of an orca killing a human.