Karlsson på Taket (Karlsson on the roof) is a book by Astrid Lindgren.
Karlsson is a mischievous little man who often visits Lillebror (a kid called little brother) and gets him into trouble. He lives in the apartment block and everything seems completely ordinary. But Karlsson has this little button on his belly and when he pushes it a little propellor appears on his back, allowing him to fly around.
Here is a little clip from the animated series:
I think it's really cute. I like the way it's animated too :) Had you heard of this story? It's one of Lindgren's more well known stories but I've never actually read it.
the little nordic cabin