The mind of a wizard is more open to the more esoteric elements of his surroundings - this is why he is able to perceive the weave of the Great Tapestry that is the multiverse, and pull at the strings. This increased sensitivity can manifest in several ways.
During a public holiday in the small town of Wyrmbersch, the Mayor is accidentally killed by a statue which falls from the roof of the Town Hall. As shocked spectators crowd around the body, they discover that the Mayor, at the moment of death, shape-shifted into a squat, stunted humanoid figure, it's grey skin dominated by bony ridges and lumps. How long was the Mayor an imposter? And who else in the town isn't what they seem to be?