Sea creature

The sea creature (referred to as both whale and dolphin in the game files) is a creature found in the Commonwealth in 2287.

Characteristics
The creature appears to be a mutated aquatic species.

Biology
The creature likely derives from a aquatic species that mutated after the Great War. The front end is similar to a dolphin's beak, however the tail fin ends up and down like a shark's as opposed to a dolphin's flipper. The creature also lacks a dorsal fin.

Locations
Carcasses of the creature can be found beached around the wasteland on boats, rivers and the coast.

Appearances
The sea creature only appears in Fallout 4.

Behind the scenes
The sea creature found on the boat west of Beantown Brewery is possibly a reference to the original Jaws film. On the boat a skeleton with a blue jacket, blue bandanna and a machete can be found with a dead sea creature nearby. The outfit clothing and machete are very similar to the ones worn and used by Quinn in the original Jaws film, while the positioning of the sea creature matches that of where Jaws emerges and kills Quinn.

If the player character swims underneath the boat, they will also find a diving cage resting on the river bed — another possible reference to Jaws.