‘Plastic’ oil lamps were figurine types which first appeared in the Hellenistic period. They grew in popularity in the 1st – 2nd century AD. They grew out of fashion in the 4th century with the emergence and rise of Christianity. These moldmade figures, were considered the luxury items for the poorer classes, used as votive offerings, as statues in the home and even as toys for children.
For more information about the meanings of animals in Roman art, see our relevant blog post: Animal Symbolism in Roman Art.