Parents from around the world hold a congress to discuss how to deal with their misbehaving children. All parents come together — only one set is missing, the parents of Sylvester, the best boy in the world. The congress decides to go see him so he can lead the other children by example. Sylvester is truly an exceptional child, but his "being good at all times and under all circumstances" somewhat gets out of hand.
Unfortunately the movie The Boy Who Became a Cupboard is not yet available on HBO Max.
| Crew | Jindřich Vodička | Dramaturgy |
| Visual Effects | Jarmila Doubravová | Animation |
| Visual Effects | Jaroslav Doubrava | Animation |
| Editing | Jiřina Pěčová | Editor |
| Visual Effects | Cilka Dvořáková | Animation |
| Camera | Jaroslava Zimová | Director of Photography |
| Writing | Miloš Macourek | Idea |
| Directing | Jaroslav Doubrava | Director |
| Visual Effects | Jiří Plass | Animation |
| Sound | Jan Kacian | Sound |
| Writing | Jaroslav Doubrava | Screenplay |
| Visual Effects | Judita Michlová | Animation |
| Sound | Ferdinand Havlík | Music |
| Production | Jiří Soják | Production Manager |
| Visual Effects | Pavla Müllerová | Animation |
| Art | Adolf Born | Graphic Designer |
