A police procedural novel can be even funnier if the police include Trolls and Dwarves and things like that. You start looking at the whole basis of the cop novel. You get the cop moving in a different way when you've actually set it in a fantasy city.
Terry PratchettHumans had built a world inside the world, which reflected it in pretty much the same way as a drop of water reflected the landscape. And yet ... and yet ... Inside this little world they had taken pains to put all the things you might think they would want to escape from - hatred, fear, tyranny, and so forth. Death was intrigued. They thought they wanted to be taken out of themselves, and every art humans dreamt up took them further in. He was fascinated.
Terry Pratchett