The 4th century Roman poet Rufius Festus Avienius, writing on geographical subjects in Ora Maritima ("Seacoasts"), a document inspired by a Greek mariners' Periplus, related that the Oestriminis (Extreme West in Latin) was peopled by the Oestrimni, a people who had been living there for a long time; they had to flee their homeland after an invasion of serpents.
The expulsion of the Oestrimni, from Ora Maritima: The "serpent people" of the semi-mythical Ophiussa in the far west are noted in ancient Greek sources.
Some believe that the dragon sometimes represented as a griffin, from the original Winged Serpent, or Wyvern (the traditional Portuguese Serpe Real), old crest of the crown of the Kings of Portugal and later of the Emperors of Brazil, is linked to local people or to the Celts who had previously invaded the area and could also have been the influence for the Ophi cult.
A legend relates that on the summer solstice a maiden-serpent, a chthonic goddess, reveals hidden treasures to people journeying through forests.
During the rest of the year, she would change into a snake living under or among rocks, and shepherds would set aside some milk from their flocks as an offering to her.