I bought a set of these a while ago, but didn't use them because they were too small for what I wanted. They would probably be a good fit for a MoT. They may be a bit too big for a horror model, but I'm not sure on the actual size of the horror. Maxmini link
These ones are bat wings, and look to be a better size. Dragonfly wings
They even do dragonfly wings
Hopefully you find something that suits what you need.
edit: Second thoughts, the first set of wings would probably be way to big for a regular horror.
Be Just and Fear not.