Probably A Very Out There Idea But It's Past 3 Am Here So I'm Blaming It On That - Tumblr Posts

Slightly obscure (?) fairytale: King Lindworm

In a long ago kingdom, the queen gives birth to twin boys. The younger is perfectly normal in every way. The older is a Lindworm (serpentine dragon).

The main problem is what happens when the younger twin wants to go off and find a wife (or husband, that works too). The older brother has to get married first, but none of the princesses brought before him meets his criteria; mainly that none of them are willing to actually love him. After two have been killed, the king decides to find a more expendable candidate and chooses a peasant — who then succeeds in breaking the curse by showing up dressed in ten dresses on the wedding night and insisting for every dress she takes off the dragon sheds a skin which eventually strips him down to the human underneath.

It's a weird fairytale, but I kinda like it.

I'm going to say that in this au, the peasant is Fiddleford, Ford is the Lindworm, and Stan is the normal prince. The princesses don't die, but Ford does attack them when they reject him as a 'monster'. Ford has been locked up in the castle his whole life, and is unsociable and aggressive because of it. Stan is the only one able to be around him safely and calm him down when he's upset.