They say there's a ghost in the decaying house over the bend.
-- "ghost" refers to his white brindle markings (ghosts normally are white).
Fail.
Ghost in a decaying house does not say brindle or markings to me at all. I would have said like... crumbling white shutters on the dark house or something.
But a ghost makes me think more of a personality reference or haunting memory of some sort.
One of two, I heard, in fact.
-- hellhound companion
Kind of pass/fail?
This one I am iffy on because it could mean a pregnant mare or a mare with a foal, or someone with a companion. The problem is that the first reference you are using as a marking clue, while the other you are using to symbolize a companion. I would think in this case both characters would be lightly colored, and neither are.
Cold house is a great reference for the Basin, pass.
"darkness creeping in shadowed wings" just reads as a dark colored peg to me.... so darkness is a good color reference, but since Crowley's magic does not have to do with wings or flying, so I think the magic clue is more misleading than a clue, fail.
So, overall you have like 2~ good clues... but I'm still going to say fail, since you need 3 solid ones for a pass.