I'm a bit of a fan of the Grant Museum of Zoology a genuine Victorian teaching museum about anatomy which is now part of UCL. Well worth a visit and they have a series of free talks, of which the next will be on 9 July, on the evolution of monsters in the human psyche.
I often wonder about that when looking at old churches. Almost always they are full of grotesque imps, devils and monsters - and I am sure there must have been a meaning to them.
Strangely, I have found it very hard to uncover any explanations about why these peculiar things do so often appear. I'm assuming they are like momenti mori - skulls and crossbones that remind the viewer to watch for their sins, because death is inevitable. Perhaps they indicate that evil is everywhere. Anyway here are two which really caught my eye in Chartres Cathedral. I am particularly puzzled by the one at the top, which looks a bit like a horse.