Luke, a wandering cowboy capable of drawing a gun faster than his shadow, fights crime and injustice, most often in the form of the bumbling Dalton brothers, Joe, William, Jack and Averell. He rides Jolly Jumper, the smartest horse in the world and is often accompanied by Rantanplan, the stupidest dog in the universe, a spoof of Rin Tin Tin, usually guarding the Dalton brothers at their jail yet never preventing them from escaping. He refuses to smell Dalton's cloths and acts as a reverse indicator to Dalton's whereabouts.