Sivert centers on a young boy who, despite his unusually large head, saves the day.
| Actor | Role |
|---|---|
 Bjørn EidsvågNarrator (voice) | Narrator (voice) |
 Steinar SagenBoy in kindergarten (voice) | Boy in kindergarten (voice) |
 Tore SagenBoy in kindergarten (voice) | Boy in kindergarten (voice) |
 Bjarte TjøstheimBoy in kindergarten (voice) | Boy in kindergarten (voice) |