Hey, you're a monk, scribing all day, same kind of begat this, smite that. Things get boring. You doodle a little. Maybe a lot. Maybe the ink fumes are getting to you and you hallucinate. At any rate, there have been some pretty crazy things going on in the margins of manuscripts. It wasn't always monks scribing these. Mr. Chaucer had a regular scribe, Adam Pinkhurst, who did the amazing Ellesmere Manuscript of The Canterbury Tales. But he had too much to illustrate and didn't go off the rails.
These, on the other hand, go off in a big way.
See the fellow on the left. Is that an editorial on their chess playing?
There's more on Buzzfeed, including ass trumpets and penis trees. I bet "getting medieval on someone" means something different to you now.