These have no markings and I have not found anything out about them. Their bodies are pearly and they have a molded medallion on their chest/neck (unpainted). Body is otherwise undecorated. Hooves are delineated. No markings.
[Collection photos, not for sale.]
This appears to be a knockoff, having the same body mold as the lavender, above. The head is different, with horn and molded neck band.