Bowser Jr. appears for the first time in the Paper Mario in Paper Mario: Sticker Star, where he is a miniboss and usually a hindrance to Mario. He has shown to be able to Paperize just like Mario can, using this ability to remove items from the map to block Mario's progress.
In World 1-1, he fights Mario and loses, then he flies away after crumpling up the bridge. In World 4, he is fought on the boat and defeated again. On Mario's way to Bowser, he is stopped by Bowser Jr. and has to fight him on his airship for the final time in the game.
