Start the Revolution Without Me (1970)

Continuity mistake: When the two different brothers retrieve the book from the Narrator (and ultimately shoot or get shot), in almost every shot, you can tell the scenes were shot separately by looking at the background. Donald Sutherland's shots are different by the wind hitting the plants in the background; Gene Wilder's shots are different by the position of the sunlight (i.e. one is dark, the other is fully lighted). Obvious if you look closely.

Duke d'Escargot: I warn you gentlemen, I am not to be trifled with. To pull the tail of a lion is to open the mouth of trouble and reveal the teeth of revenge biting the tongue of deceit.