"Through the grasses covering the glade walked - no, not walked - floated a queen, radiant, golden-haired, fiery-eyed, ravishing. The Queen of the Fields, decorated with garlands of flowers, ears of corn, bunches of herbs. At her left-hand side a young stag pattered on stiff legs, at her right rustled an enormous hedgehog."
Dana Méadbh (corrupted as Danamebi) is the elves' name for a goddess also known as the Eternal One, Queen of the Fields, Lyfia, and Bloemenmagde by the dwarves. She communicates telepathically with those she encounters. She appeared in the short story The Edge of the World. In that short story, her avatar is Lille.
According to the ancient book known as Physiologus, Dana Meadbh may appear during the summer, more or less from Belleteyn to Lammas. Geralt reads this out loud from the tome:
"Glimpsed she may be during the time of sumor, from the days of Mai and Juyn to the days of October, but most oft this haps on the Feste of the Scythe, which ancients would call Lammas. She revealeth herself as the Fairhaired Ladie, in flowers all, and all that liveth followeth her path and clingeth to her, as one, plant or beast. -"