This item originally came from Almeg, who is the Goat of the Gods and nominally owned by Blind Io. He sacrificed one horn, originally to feed the children born to Io and Bissonomy. This horn became the Horn of Plenty, the Cornucopia, which is now the badge of office of Summer, and was briefly in the keeping of Tiffany Aching when she contracted avatarism as well as ped fecundis.
The Cornucopia carries the Ephebean text π'αητα π'ο'γ επιτη'ειξ, cηαπ'ιζτη 'ειο'επα 'ονομα. μεγαλθπθ εγετελλομι!
("p'anta p'o'ey epith'eix, chap'izth 'eio'epa 'onoma. megaloni eyetellomi!" or All you desire, I give upon a name; I grow, I shrink)