The White Bull
The story is based on the Greek mythological tale of Europa and the bull, where the white bull is the king of the Greek gods, Zeus, in disguise. Zeus, the sky and thunder god of the Olympic pantheon, often wore a disguise when romantically pursuing mortal women, so as to avoid the eye of his wife and sister, Hera.
History of zoophilia
Several Greek myths include the God Zeus seducing or abducting favoured mortals while in the form of an animal: Europa and the bull, Ganymede and the eagle, and Leda and the Swan. Only the latter legend includes actual copulation between Leda and Zeus in his animal form, but depictions of this act, fairly uncommon in antiquity, became a popular motif in classicising Renaissance art, contributing to a lasting prominence in Western culture.
Various classical writers recorded that bestiality was common in other cultures. Herodotus was followed by Pindar, Strabo and Plutarch in alleging that Egyptian women engaged in sexual relations with goats for religious and magical purposes - the animal aspects of Egyptian deities being particularly alien to the Greco–Roman world. Conversely, Plutarch and Virgil make similar accusations of the Greeks, with Plutarch writing in his "Discourse on the Reason of Beasts" that they committed "very frequently and in many places great outrages, disorders and scandals against nature, in the matter of this pleasure of love; for there are men who have loved she-goats, sows and mares."