Primadonnan was a human character on Svenska Sesam. Her name means "The prima donna" in English.
Primadonnan is the absolute star at the Gala theater, and is in fact the only regular actor at the theater. She's fully aware of the fact, and behaves accordingly. In one episode, she could not rehearse the play, since the other actors had not showed up. So she presses the theater staff into rehearsing with her. Dirren is ready to do anything in order to keep his star happy.