This is a knockoff version of the Gi-Go mold. Most of them have the same trio of hearts symbol. Click images to enlarge.
Inset Glass Eyes:
These are very good imitations of Gi-Go, but this mold has different hoof markings (MADE IN CHINA on single back hoof):
The following are made of a slightly harder plastic, and are marked MADE IN CHINA on the belly; hoof markings have been removed. Sometimes they have a painted mark of Polyfect Toys. They tend to have more of the white of the eye showing around the iris than true Gi-Gos: