I've found a treasurebox of images of the tiny sketches in medieval illuminated manuscript margins. Often called "drolleries" or "grotesques," they are full of fantasy, humor and earthiness. Since the main illustrations generally concern the sacred or the noble, it's as though all the rest of life spilled out to surround them. As it does. The site is Discarding Images. Here's some of the treats to be found:
A cat playing the hurdy-gurdy (be sure and check the link to the "much cuter cat"
And a cat playing the bagpipes
A hare family under the most beautiful sky
A dinky little dog
another dinky dog in a tree
A cross-eyed winged cat
You'll see so much more at this excellent site. Enjoy.