What is an allusion from Act I, Scene 4 of Romeo and Juliet?

Act I, Scene 4 of Shakespeare's Romeo and Juliet is noteworthy because of Mercutio's outlandish Queen Mab speech in which he is basically teasing Romeo about his unrequited love for Rosaline. The most important allusion in this speech is that of Mab. Although the origin of this name is not clear, it is most likely of Celtic origin. According to Daniel Augustus Beaufort's Antient Topography of Ireland, Mab was the chief of the Irish fairies. Shakespeare may have been the first to call Mab "Queen," but the title also appears in contemporary works such as Ben Jonson's "masque" (a little-used genre of performance which included speech, dancing, and spectacle) The Satyr. Mab is a "fairies mid-wife" because she delivers the dreams of sleeping men and women. Queen Mab has often been used in literary works after Romeo and Juliet, especially in Shelley's long poem Queen Mab; A Philosophical Poem; With Notes. Numerous other allusions are contained in the speech, including the "small gray-coated gnat," referring to the "gray fly" of Milton's Lycidas and the "tithe pig's tail" which alludes to the practice of giving a priest a pig as part of the payment of tithing (contributing ten percent of one's income to the church).