The curry monster is from Red Dwarf (and is defeated by a can of lager - because everyone knows that lager kills a good vindaloo).

The dragons are from Discworld - and explode when they hiccup.

In Great Waters is the mermaidy one. It's a book by Kit Whitfield - whose previous book, Bareback, featured a world made up almost-entirely of werewolves, where the non-wolves were the odd ones.