In one of the film's most memorable scenes, Ephraim grabs a seagull and viciously hammers the creature's body against a rocky surface — multiple times — until it's nothing but feathers and splatter residue. At the end of the film, a flock of seagulls appear and feast on his innards, which is a gross-out moment that recalls the nautical folk tales of old. As Den of Geek noted, Eggers turned to maritime lore while researching "The Lighthouse," and it informed much of the story. For a start, the film's bare-bones premise was inspired by a real-life murder case involving two Welsh lighthouse keepers in the early 19th century. Other aspects of the film were informed by sailor diaries, fiction, and paintings from the era. 

The ending, however, is an example of a sailor's greatest fear come to life. In seafaring lore and superstition, seagulls are believed to possess the spirits of deceased sailors, and killing one of them is a bad omen that could spell dire consequences for the culprit. Therefore, the closing moments of "The Lighthouse" can be interpreted as the spirits avenging their fallen friend (just don't ask Robert Pattinson what it all means). 

This isn't the only legend that's explored in the ending of "The Lighthouse," either.