Who is Karlsson?

Karlsson-on-the-Roof is a character who figures in a series of children's books by the Swedish author Astrid Lindgren. Lindgren may have borrowed the idea for the series from a similar story about Mr. O'Malley in the comic strip "Barnaby" (1942) by Crockett Johnson.

Karlsson is a very short, plump and overconfident man who lives in a small house hidden behind a chimney on the roof of 'a very ordinary apartment building on a very ordinary street' in Vasastan, Stockholm. When Karlsson pushes a button on his stomach, it starts a clever little engine with a propeller on his back, allowing him to fly.

In his own opinion, Karlsson is the best at everything. He befriends Svante Svantesson, a 7 year old boy and youngest member of the Svantesson family.