Also known as the moustached whale or Mysticeti, the baleen whale is the largest species in the whale family capable of growing up to 190,000 kilogrammes (420,000 lb) in weight and 33.5 metres (110 ft) in length. The baleen whale is characterised by having baleen plates, a sieve-like device, instead of teeth, for philtre feeding krill, copepods, plankton, and small fish.

Baleen whales include blue, gray, humpback, minke, bowhead, and right whales. Many baleen whales species are endangered.