Baubo is an old woman in Greek mythology who jested with Demeter when she was down.
In his 'Greek Myths', Robert Graves writes that Demeter (in disguise) was the guest of King Celeus in Eleusis. The lame daughter of the King, Iambe, "tried to console Demeter with comically lascivious verses, and a dry nurse, old Baubo, persuaded her to drink barley-water by a jest: she groaned as if in great travail and, unexpectedly, produced from beneath her skirt Demeter's own son Iacchus, who leapt into his mother's arms and kissed her." (Robert Graves, The Greek Myths. (London: Folio Society, 1996) 2 Vols. Vol 1, p.92) Graves writes, "Iambe and Baubo personify the obscene songs, in iambic metre, which were sung to relieve emotional tension at the Eleusian Mysteries; but Iambe, Demeter, and Baubo form the familiar triad of maiden, nymph, and crone. Old nurses in Greek myth nearly always stand for the goddess as crone." (p.96)