Whales and Dolphins are ocean mammals. They are both from the same family, CETACEA (sey-tay-sha.)  All ocean mammals, breath through a blowhole located at the top of their head.

They are called mammals because they have lungs not gills, hair not scales, they also give live birth, don't lay eggs, and they nurse their young. There are only about 80 species of whales and dolphins.

Killer Whales can be very vicious mammals. They often eat other whales, fish and can also devour seals, and porpoises.

Killer whales can be 20 to 30 feet long. With their  40 to 48 sharp teeth they can rip out chunks of blubber  from whales of any size.
Killer whales are very smart mammals. They are very fast learners. Killer Whales are sometimes caged at theme parks.  They like people and they like doing tricks for them.

Sometimes when swimming , killer whales look like large whales, or even harmless Pilot whales. But you can tell the difference by looking to see if they have a smooth black body with a soft white belly and a white patch right above they're eye.

You can find killer whales in most of the world's oceans, but a lot of them like the cold polar seas where seals and fish can provide year long food.