Munro (1961)

"Munro" is your stereotypical, stroppy, four year old kid who wants nothing but to be left alone to play with his ball. Then he gets a letter from the Draft Board welcoming him to the US Army! He goes for the physical and listens to all the malingerers certain that surely they can't admit a small child who can't even unbutton his own tunic. Passed 1A, off to boot camp he goes and is soon listening to the clipped tones of his drill sergeant and playing a quite dizzying game called "face". His protestations only lead to him joining the sick pool temporarily, and all his attestations of youth fall on incredulous deaf ears. Now he's got no choice - a soldier he must be or, maybe, he should just resort to doing what 4-year-olds do best when they are unhappy...? The animation is a little basic, but the witty narration and the sheer ridiculousness of the plot makes this really quite good fun to watch.