Conversation so far:
Tell me about Orca whales.
Orcas, or killer whales, are the largest of the dolphins and one of the world's most powerful predators. They're immediately recognizable by their distinctive black-and-white coloring.
Are Orca whales really whales?
They are often confused for being a whale because of their name 'killer whale', but did you know that orcas are actually dolphins? In fact, they are the largest member of the dolphin family!
How do Orca whales hunt?
Knowing this, the orcas will grab gray whales and attempt to drag them into deeper water, or cooperate to block the path to the shallows. When the orcas do catch a grey whale, they will kill it by drowning, holding the whale's blowhole underwater until it expires.
What do Orca whales eat?
Killer whales feed on sea birds, squid, octopuses, sea turtles, sharks, rays and fish. They also eat most marine mammals, such as seals and dugongs.

Question: Where did they get their name?
Self-contained rewrite: Where did Orca whales get their name?