Dolls of All Nations
A clockwork display in Crumley's toy shop in the Maul, set up to display the joys and delights of Hogswatchnight to the little children of Ankh-Morpork. A complex piece of clockwork, it should feature dolls dressed up as (human) children of all races and nationalities linking hands and joining in together in the anthem "Wouldn't it Be Nice If Everyone Was Nice".(Well, you could TRY having little Trolls and Dwarves holding hands and proclaiming brotherhood, but in a city where everyone knows about Koom Valley, it wouldn't work)
Unfortunately, after the unscheduled arrival of the stand-in Hogfather plus sledge drawn by four enormous and incontinent boars, the trauma delivered to the dolls is so great that they go haywire and the little Howondalandese Boy, for instance, is then observed to be pummelling the little Überwaldean Girl with his ceremonial spear.
Terry Pratchett must really hate this sort of thing, as in the Johnny Maxwell books, there is an account of a similar display in the Neil Armstrong Shopping Mall in Blackbury being destroyed, with similar unintended results of mayhem and destruction, by Bigmac and Wobbler trying to see if they could make it go faster.
All those sick-making and nauseous songs about universal love and brotherhood that seem to come out at Christmas... the New Seekers' "I'd Like to Teach the World to Sing", for instance, or Ray Stevens' "Everything is Beautiful(Jesus Loves The Little Children)"
Or the infamous 'It's A Small World' ride at Disney.