The term 'DOLPHIN's cousin' refers to three aquatic mammals: the ORCA (also known as the killer whale), the GRAMPUS, and the PORPOISE. The ORCA is a large black and white whale that can be found in all oceans of the world. The GRAMPUS is a species of DOLPHIN that is found in the Atlantic and Pacific Oceans. The PORPOISE is a small toothed whale that is found in coastal waters around the world. All three of these animals are closely related to dolphins and are considered to be their cousins.