Hieronymus Bosch actually painted him in there originally. It totally wasn't me. Just now. In Gimp. Raging because I had the wrong layer selected for like an hour.

I learned a lot about Gimp from doing this one. Making sure you have your layers selected correctly is important for avoiding moments of rage like “wy am Selekshun no do nothun?!” The original file for the painting was uber massive, around 7K by 4K, and Waldo pics abound, so content hunting took like two seconds. Just take your inserting pic, right click, layers, add alpha channel(makes it transparent), or something like that, then use the magic wand tool or the free form selection to cut out the object in question, using edit then clear to erase it. Then scale and place your objects. Pretty straightforward.

I felt that Waldo was too natural a fit for slipping a stranger into a strange picture to NOT use him. And Bosch is just a beast anyway, so. I mean, how HARD® is a guy who paints an ear knife and a snake knight riding a flying fish? Game. Set. Match.