You Shall Not Give False Testimony, Except for Profit

 is a mission in Red Dead Redemption.

Walkthrough
You meet up with Nigel in Armadillo. He gets you to drive his wagon to Ridgewood Farm while he explains what he wants you to do. Just before you get to the Farm he drops you off so you are not seen showing up together. Approach Nigel as he goes through his pitch. He will "randomly" pick you out of the crowd to sample his tonic. He then asks you to shoot a cow skull that is on the porch of the Farm. A big fella, Aquila, challenges you to shoot his hat while it is in the air. Use your Dead Eye to shoot the hat with a couple of bullets. The big fella then takes offense to you shooting holes in his hat, and you have to fight him using your fists. After the player has beaten him with his fists Aquila draws his weapon, the player will have to disarm him. The pistol must be shot out of the hand of Aquila by using the Dead Eye.

Trivia

 * After this mission, if you walk over to West Dickens and aim at him or take other aggressive action, he will try to escape or shoot you if you shoot at him. He is invincible though and cannot be killed.