Teenage Caveman

Robert Vaughn said in an interview that he considered this to be the worst film ever made.

Near the beginning of the film, the Symbol Maker (Leslie Bradley) asks his woman, "Where's the boy? Beyond the river?" The left sleeve strap of the Symbol Maker's fur outfit is sewn together. In the next scene, the strap comes undone and he is holding the strap under his left arm. In the next scene, the strap is now tied together with a leather shoelace. Later in the film, this strap is shown tied together in two different places. Apparently there were problems keeping this sleeve strap together throughout the entire film, because it changes constantly.

Edited from One Million B.C. (1940)