The First Bad Man (1955, animated short)

The First Bad Man is an American animated cartoon directed by Tex Avery, and features narration by singing cowboy Tex Ritter. It was released by MGM on September 30, 1955.
Notes:
Ed Benedict provided uncredited layout designs for this cartoon. Benedict would later work for Hanna-Barbera Studios (which was started by MGM alumni William Hanna and Joseph Barbera), where he would use some of the caveman designs from this cartoon as the basis for characters in The Flintstones.
The Wacky World of Tex Avery used this short as the primary inspiration for Einstone, one of the show's characters.