Well, he might have. The Telegraph reports that a museum director in Norway bought a painting at auction signed "A. Hitler." To his surprise, there were three bonus drawings inside: two of the dwarfs from "Snow White" and one of Pinocchio. The dwarfs were signed "A.H." The Pinocchio is unsigned.
As evidence that the "A.H." doesn't stand for "Albert Horowitz," let us consider the following: Hitler owned his very own copy of "Snow White" and thought it "was one of the best movies ever made." He did try to make it as an artist before turning to, um, politics. Plus he loved dogs! Come on, it's gotta be him.
photo: Daily Telegraph 