- Chinese episode title: "粗心天鹅湖" ("Cuxin Tian'e Hu")English episode title: "Careless Swan Lake" (Lookus's English dub)
Smart S. hurts himself by slipping on a banana peel while practicing for a play at his school; Careless S. takes his place as the prince in the play. This inspires Big M. to try to mess up the play by using a machine to dispense banana peels all over the stage.
"Careless Swan Lake" contains the following tropes:
- Banana Peel: Smart S. slips over one, forcing him to swap roles with Careless S. in the play. Big M. tries to scatter banana peels on the stage to make everyone slip.
- Bandage Mummy: Smart S. is covered almost entirely in bandages when Sweet S. treats him after his injury.
- Breaking the Fourth Wall: Little M. questions whether the idea of slipping people with banana peels would be childish. Big M. replies that this is a cartoon, so it can't be too complicated.
- Playing a Tree: Careless S. initially plays a tree in the play. Come Smart S.'s injury, he swaps roles with him.
- School Play: The heroes put on a school play for the president of planet Xing Xing.
- Shout-Out: The play the heroes put on is Swan Lake, plain and simple. It's got the princess turned into a swan and the owl wizard and everything.
- The Show Must Go Wrong: Big M. summons a monster out of his banana peel machine, thus significantly messing with the play.
