In The Lighthouse, when Ephraim Winslow ascends to the lighthouse and tries to see what exactly is at the top, he sees a tentacle slithering on the surface.
Then again, in one of the fight scenes, one before Winslow buries Thomas (Willem Dafoe) alive, Thomas tries to choke Winslow using his tentacles.
I don't understand what those tentacles signify in these scenes. Is Willem Dafoe a mermaid/merman? If yes, then why does he have tentacles?
Now I know, these creatures are totally fictional but in my knowledge Mermaids or Mermen don't have tentacles. And I don't think the director would go out of his league to give tentacles to a merman just to show the audience something uncanny, even though the entire movie is pretty mysterious & strange.