Despite never having formal art education Max Ernst (1891 - 1976) helped found the Cologne Dadaist group and later became a famous surrealist painter.
What's surrealism? Wikipedia explains:
Surrealism is a cultural, artistic, and intellectual movement oriented toward the liberation of the mind by emphasizing the critical and imaginative faculties of the "unconscious mind" and the attainment of a state different from, "more than", and ultimately "truer" than everyday reality: the "sur-real", or "more than real".
For more of Max's artwork, visit: Link| The Surrealist Website (via Ursi's Blog)