From the ‘Weird stuff found on eBay’ department (link).
To coincide with the release of the 1989 Batman movie, some joker at Eurostudio allowed this to happen:
Whenever creepy licensed art like this pops up, the same questions arise: who was the artist? Who picked the images to use? Who bought this? Who did they think would want to decorate their room like this? Is it terrible or awesome?
There’s not much more I can say about this that the wallpaper doesn’t say itself. I do think it’s both considerate and telling that they made it spongeable, given that the first reaction of people to seeing a room covered in this would be to either explosively throw up or jizz.