Complex sentence: Stefán Karl Stefánsson (;) (born 10 July 1975) is an Icelandic actor, best known for playing the villain Robbie Rotten on the children's television series "LazyTown".
Split into simpler sentences: Stefán Karl Stefánsson (;) (born 10 July 1975) is an Icelandic actor. He is best known for playing the villain Robbie Rotten on the children's television series "LazyTown".