 Whales have torpedo shaped bodies with non @-@ flexible necks , limbs modified into flippers , non @-@ existent external ear flaps , a large tail fin , and flat heads ( with the exception of monodontids and ziphiids ) . Whale skulls have small eye orbits , long snouts ( with the exception of monodontids and ziphiids ) and eyes placed on the sides of its head . Whales range in size from the 2 @.@ 6 @-@ metre ( 8 @.@ 5 ft ) and 135 @-@ kilogram ( 298 lb ) dwarf sperm whale to the 34 @-@ metre ( 112 ft ) and 190 @-@ metric @-@ ton ( 210 @-@ short @-@ ton ) blue whale . Overall , they tend to dwarf other cetartiodactyls ; the blue whale is the largest creature on earth . Several species have female @-@ biased sexual dimorphism , with the females being larger than the males . One exception is with the sperm whale , which has males larger than the females . 
