Not mine, they’re all in the finest of taste always… But from a classic novel, The Devil Rides out – where the group of Satanists are summed up as (to paraphrase): "a bunch of epileptics and other abnormals" that being at the root of their depravity…. Which considering it was written post-WW2 makes it even more unpleasant to read.
Didn’t finish Heart of Darkness for similar reasons, the pervasive sense that the locals amounted to less than the whites was just unpleasant to read so I stopped, making it the shortest book I never finished I believe.