"Well, well, well, if it isn't Slublo and Stinky Mustard!"
Poor Katy, life is not kind for her. You know, this episode is quite an ambitious one, it has many things going on: the prank on Katy, the dance battle with the rival mascots and Mr Wubhamer's reaction to what they've done. And all of them need to go together without seeming like they were all just tossed on the same video file.
And in my opinion, it was well done. One event leads to the next in a way that makes sense but leaving enough space for the next one to stay a while on the spotlight. Usually when there's too many things on the story either one of them gets too much attention, or they all get too little attention or they look completely unrelated. But these were avoided by making one event being the cause of the next and all of them being modular enough so that the last doesn't stay on mind during the current (another lesson to be learned).