Queen Mab is a fairy referred to in William Shakespeare's play Romeo and Juliet, in which the character Mercutio famously describes her as "the fairies' midwife", a miniature creature who rides her chariot (which is driven by a team of atom-sized creatures) over the bodies of sleeping humans during the nighttime, thus helping them "give birth" to their dreams.
A popular theory holds that Mab derives from Medb (pronounced "Maive"[1][2]), a legendary queen from 12th-century Irish poetry; scholar Gillian Edwards notes "little resemblance", however, between the two characters.
[3][2] Thomas Keightley suggested a connection to Habundia or Dame Habonde, a goddess associated with witches in medieval times and sometimes described as a queen.
She is the fairies' midwife, and she comes In shape no bigger than an agate-stone On the fore-finger of an alderman, Drawn with a team of little atomies Athwart men's noses as they lie asleep; Her wagon-spokes made of long spinners' legs, The cover of the wings of grasshoppers, The traces of the smallest spider's web, The collars of the moonshine's wat'ry beams, Her whip of cricket's bone; the lash of film; Her waggoner a small grey-coated gnat, Not half so big as a round little worm Pricked from the lazy finger of a maid: Her chariot is an empty hazelnut Made by the joiner squirrel or old grub, Time out o' mind the fairies' coachmakers.
This is that very Mab That plaits the manes of horses in the night, And bakes the elflocks in foul sluttish hairs, Which once untangled, much misfortune bodes: This is the hag, when maids lie on their backs, That presses them and learns them first to bear, Making them women of good carriage: This is she—" — Mercutio in Romeo and Juliet, Act I, scene IV Since then, Queen Mab re-appears in works: