• Whales breathe in air above water into their lungs.
• They have hair on their bodies (although it is very little).
• They are warm-blooded animals (they maintain a high body temperature).
• They have mammary glands.
• They have a four chambered heart.

Whales are classified into 2 groups, the toothed whales, like the Killer whale or Orca and Beluga, and the baleen whales, like the Humpback whale and the colossal Blue whale.