Final Fantasy III NES Monsters

I am playing thorugh Final Fantasy III for the NES/FAMICOM for the first time, and I have to say that I am enjoying it very much. However, I have a couple of questions about where to find some monsters.

1. Where is the monster Dullahan? I have looked around Hyne castle for hours on all floors and cannot find it. Does anyone have any suggestions or know what areas it is most common in?

2. I have looked through the monsters section from multiple websites and they all have some monsters that puzzle me, such as Captain, Fury Eye, Hobgoblin, etc. Do these monsters actually exists in the game, since it seems that no one has actually found them? Are they in the game coding, but not in the actual game? Does anyone know anything else about theM/

Thanks for any helpanyone can provide!

Dullahan is in Hein's castle, he's just very rare encounter.

Hobgoblin and such aren't really in the game I think, they are edits, like Terrible Dragon.

I kind of thought the same thing, but then I asked myself why every site would put them in their monsters section and them not be real?

Thanks for replying!