I once ran a game of Dagger (kid-friendly OSR clone compatible with most old rules) for my kids. They still remember it. Thinking back on that gave me an idea for a book. I'm having both of my daughters (now 13 and 11) do illustrations, 15 each, for a small bestiary that I will stat and describe for OSR-compatible games, most likely using Swords & Wizardry as the basis for all the statistics. I will take their pencil drawings, ink them, add a few details, and scan them to use as the pictures for the monster stats.
The craziest thing my youngest daughter has drawn so far is a snowman with a top hat, an axe, and a chainsaw! I told them to go nuts and draw whatever they like as long as it's a monster. We even have a sea sponge that has eyes in the holes of its body and walks by moving its mouth, using its teeth like so many legs. Insane, wonderful things are going to be in this book!
I plan to make this available for a small price in PDF and, as long as I can figure out what I'm doing, print on demand.