Medium Dave Lilywhite, along with his brother Banjo, are two of the thugs that Mr. Teatime (who insisted that his name be pronounced teh-ah-tim-eh and not like the afternoon meal) employed to help him kill the Hogfather. By the barely educated standards of Ankh-Morpork's differently legal society, Dave was considered an intellectual, largely because he had proper spelling for his tattoos.The Lilywhite boys came from a tough background. Their mother was the terrifying Mrs. Lilywhite who was well respected amongst the criminal classes of Ankh-Morpork. An enormous woman with a punch that a troll would envy, she was known to have killed at least one person, Glossy Ron, She died holding off the Watch, her last words to her son Dave were "I'll hold 'em off and if anything happens to me, take care of the dummy (meaning Banjo)!" Dave, like both boys, was terrified of his mother so took these words as gospel, protecting his brother for fear of the wrath of his mother from beyond the grave - a threat that ultimately came true. Ma Lilywhite, as worst nightmare of both boys, made a special appearance at the Tower of Teeth (which explicitly drew on one's worst fears to terrorise intruders). She chastises Banjo for playing with girls and Dave for not looking after him properly. Ultimately, Dave's fear of his mother leads to his death, he is killed by his imagination when the Tooth Fairy puts his mother inside his mind.
Pratchett often plays on size in his novels, usually in connection to the Mac Nac Feegles - Wee Big Jock, etc. In this case he plays on the standard gangster style names like "Big Jim" Colosimo ( a Chicago gangster in the prohibition era) by giving it a twist - Dave isn't Big or Small, he is Medium.
On Roundworld the "Lilywhite Boys" are part of the old English folk song, Green Grow The Rushes, O which relates to the bible and is a cumulative counting song, with each verse built up from the previous verse by appending a new stanza. Like all folk songs there are many variations but the usual version in its entirety it goes:
- I'll sing you twelve, O
- Green grow the rushes, O
- What are your twelve, O?
- Twelve for the twelve Apostles
- Eleven for the eleven who went to heaven,
- Ten for the ten commandments,
- Nine for the nine bright shiners,
- Eight for the April Rainers,
- Seven for the seven stars in the sky,
- Six for the six brown walkers,
- Five for the symbols at your door,
- Four for the Gospel makers,
- Three, three, the rivals, oy!
- Two, two, the lily-white boys,
- All dressed up in green, Ho ho
- One is one and all alone
- And evermore shall be so.
There are detailed explanations and theories on the various lines and their symbolism, some obvious, some less so. The most common explanations for the lines about the Lily-White Boys (babes in some versions) are that they are Jesus and John the Baptist, the constellation Gemini with Castor and Pollux the Twins a sign of spring, the holly and the ivy (although the holly berry is red and the ivy berry is black, both have white wood and are evergreen) or the holly and the oak, the Old and New Testaments. Another version calls them lilly white babes with the suggestion that this is Adam and Eve while another refers to lilly white doves as in Noah's Ark. Whatever the case may be, Pratchett is clearly playing with the idea of these vicious thugs who live at the Young Men's Pagean Association being the antithesis of innocence and Christianity while also playing on Banjo's innocence and eventual redemption - a very christian theme.