In Greek mythology, the surname “Erinys” (Furious) was given to Demeter after a traumatic event in which she was pursued by Poseidon, who desired her.
In order to escape his advances, Demeter transformed herself into a mare and mingled with the horses of Oncius. Poseidon, not to be outdone, also transformed into a stallion and pursued Demeter. The goddess was furious about this chain of event and gained the nickname “Erinys” due to her anger.
The Arcadians referred to someone who was wrathful as “being furious.”
As a result of this encounter, Demeter gave birth to the horse Arion.
In the sanctuary of Demeter in Onceium, there was a nine-foot statue of her holding a chest and a torch in her right hand. This statue was a testament to the goddess’s fierce and protective nature.