Discworld is a setting where belief in things is a quantifiable resource, so during a disaster that freed up a lot of normally bound belief, a number of new deities started appearing. Deities of things that *could* have gods associated with them, such as warts between the toes and hangovers, if people weren't busy believing in other things.
During the crisis some wizards perform an experiment to explore the effects of the disaster, and they successfully - accidentally? - will into being the god of the sock that always goes missing in the laundry. Incarnated as a brightly coloured and slightly tapir-like being that dwells in dark basements and ravenously devours exactly one of each pair of socks...