So, there’s been a lot of speculation about who Dr. Whale is, and personally, I love the idea of him being Frankenstein, though he could be a god, such a Poseidon.
In another thread, someone suggested that Dr. What’s might be from another realm (a “horror realm,” assuming he’s Frankenstein), explaining why Whale said Charming wasn’t his prince. So, after looking back at the pictures of the doors, I thought maybe he could be from door 9. Really it could be a few of them, though. But the writers did release information that Regina was able to affect other realms besides the EF, which was how she brought Jefferson to SB. Maybe this was how Whale came to SB.
Now, if he’s Poseidon, I definitely think he could be from door 8. I know we’ve theorized that this door could be the Little Mermaid, but… Maybe not. Technically, the Little Mermaid happened in our world, and if it was The Little Mermaid’s door, what would we find behind it? Water? Seems to me that a world for Poseidon, or Whale, makes a little more sense.