The Mystery of the Missing Five - S1.E3

Irascible Four must always look after his little twin brother Five. But, when Five's behavior includes eating Four's favorite toothpaste and polishing his ankles with Four's favorite toothbrush, Four does the unthinkable when he thinks Five isn't his brother anymore and blurts out that he wishes Five had never been born. Seven tells Four that he hurt Five's feelings. Mama crosses her arms and is very unhappy. Five thinks he's a bad boy and a good boy. When Five disappears, the Monsters think that Five has gone to the hospital to "Give himself back!" when it makes Four cry. The hunt is on when Four learns that an annoying Five is better than no Five at all. When he comes home crying, he wishes Five hasn't been his brother anymore, and One, Two, Three, Four, Six, and Seven begin to cry. So it's up to One, Two, Three, Four, Six, and Seven to get Five back.