The present post presents images from the Demon series that I found on the internet. Having viewed many of the paintings in Russia several years ago, I can assure you that they are large and quite impressive when seen in person. That said, some of the images below can be enlarged by clicking on them, though the impact is nothing like that of the real things.
Various Internet sites present this in different color schemes, so I don't know what the original colors were.
Wikipedia link here.
Probably Vrubel's most famous Demon painting. Wikipedia entry here.