Our initial survey of stained glass across Canadastraddles 5000 kilometres and 600 years—from the Pacific to the Atlantic, from the 16th to the 21st centuries—albeit with a gap of some 350 years. (Annotated)
We found only two or three "real" demons in stained glass, creepy humanoid creatures with mean faces.
This scaly specimen was made back in 1170 for the Cathedral at Troyes in France. It is now at the Victoria and Albert Museum in London where we took the photo.
You should be able to spot another gremlin (complete with horns), since he—or it—appears several times in the slide show. He/it was also made in France, about 800 years later, and can be seen in St. Anthony's Church in Regina.
Watch for demons in other guises!
These days demons are usually symbolized by snakes, dragons and similar reptilians. Angels, fortunately, still look like angels.
Most of our angels and demons are from churches in Canada and France.