The killer whale, or the Orca, is the largest whale in the dolphin family. It has a very tall dorsal fin which can grow up to 1,8m (6ft). The Orca is one of the most wide-ranging mammals on earth; mostly seen in the polar regions but can be found in all oceans. Killer whales have one of the most varied diets of all cetaceans, eating anything from fish, squid, birds, sea turtles, to seals and dolphins. It can even take on blue whales and some orcas have been known to attack Great white sharks.