What is this thing?

There's a painting I saw hanging in a museum in Amsterdam which had a suspicious attribution (claiming to be from before when the attributed artist (Adolphe Willette) was born...) It's an amazing painting, and it kind of lines up with Willette's other crazy bonkers style, but I have looked far and wide for an official attribution, or an official print (because I want to hang it in my house)... The only solid connection seems to be that many people see this exact painting at this exact museum and all want to know more lol

The giant attack-on-titan style cat, the wizard, the general chaos... It's perfect. Similar feeling of "How is this not more widely known?"