Despoina, whose name means "Mistress", is a goddess in Greek mythology. Despoina is not the goddess' true name, which is only revealed to those initiated in the Eleusinian mysteries. Despoina was the daughter of Demeter and Poseidon. Demeter had taken the form of a mare in order to escape Poseidon, by hiding among a pack of other horses. However, he saw through her guise and turned himself into a stallion, mating with her. Despoina and her brother Arion (an immortal, talking horse) were born from their union. Despoina and Arion are the half-siblings of Persephone, who is Demeter's daughter by Zeus.