ocean sunfish
Common name for the Molidae family of fishes, also commonly known as Ocean Sunfishes.
Their body shape comes to an end just behind the dorsal and anal fins, giving them a "half-fish" appearance.
The most Famous members of this family is the Ocean Sunfish (Mola Mola) and the Southern Sunfish (Mola Alexandrini).
This tag will also apply for freshwater sunfish in the family, Centrarchidae.