Bronco

A bronco or bronc, in the United States, northern Mexico and Canada, is an untrained horse or one that habitually bucks. It may be a feral horse that has lived in the wild its entire life, but can also be a domestic horse either not fully trained to saddle or poorly trained, and hence prone to unpredictable behavior, particularly bucking. The term also refers to bucking horses used in rodeo "rough stock" events, such as bareback bronc riding and saddle bronc riding. The silhouette of a cowboy on a bucking bronco is the official symbol for the State of Wyoming.