His name is taken from Yosemite National Park.

He is commonly depicted as an extremely aggressive gunslinging prospector, outlaw, pirate, or cowboy with a hair-trigger temper and an intense hatred of rabbits, Bugs in particular.

Whenever he's preparing to shoot Bugs, Sam says, "Say your prayers, Varmint!", allowing the rabbit enough time to foil his intentions.

Every time Bugs dares Sam to "step across that line", he cannot help but do so, even if he steps off into empty space or down a mine shaft.

Due to his short stature, Sam has to use a set of portable stairs to get on his horse. In Bugs Bunny Rides Again, he solves this problem by riding a miniature horse.

In cartoons with non-Western themes, he uses various aliases, including "Square-deal Sam" in 14 Carrot Rabbit, "Riff Raff Sam" in Sahara Hare, and "Shanghai Sam" in Mutiny on the Bunny.

Although a similar character had previously appeared in Super-Rabbit (1943) and Stage Door Cartoon (1944), Sam's first appearance is generally considered to be Hare Trigger (1945) in which Bugs Bunny foils his attempts to rob a train.

Sam is a Confederate soldier who attempts to prevent Bugs from crossing the Mason-Dixon line, but the cartoon doesn't take place in the American Civil War. When Bugs tells Sam the war ended over 90 years ago, Sam insists, "I'm no clock-watcher!" and refuses to leave his post unless he receives orders from Robert E. Lee.

Sam teaches classes in Firearms and Anvilology (the study of falling anvils, a staple joke in the Looney Tunes universe) and is sometimes portrayed as the school principal.

Though officially a cowboy, animators often put Sam in different costumes. Some countries seem to prefer his pirate incarnation, as "Sam the Pirate" is his official name in France and a frequent alternative name in Italy.