Astrid Lindgren ( http://en.wikipedia.org/wiki/Astrid_Lindgren ) A Child meets a propeller wearing "not so imaginary" friend, voiced by Vasili Livanov ( http://www.imdb.com/name/nm0515106/ ) . Karlsson-on-the-Roof ( Swedish : Karlsson på taket ) is a fictional character in a series of children's books created by Swedish author Astrid Lindgren . The cartoon adaptation