I think horses need a rare curio upon skinning them. Exact same setup as getting a Wondrous Woodshaving, Dark Heart. ETC. I believe this curio should be a "Lucky Schlong". I am not good with figuring out what the stats of this item would be so I leave that to the Gods. Thoughts?
I dont think the animal its self should have a curio. But it would be nice to have it be one of those discoveries of riding one. Create a toy horse curio.