This is a Gi-Go mold that shows up in Wonder Pony Land (and other store brand) sets. It is similar to L-14-B1 but slightly chubbier, and L-16-B2 which has pegasus wings.. Marked L-16-B1 on bottom back hoof. Stands 5.5″ tall.
I have found the pose with earth ponies and unicorns (horn may be painted or unpainted). Usually they have the big painted eyes, but a couple have inset glittery glass eyes. Click images to enlarge.