As a working dog, Catahoulas have been bred primarily for temperament and ability rather than for appearance. As a result, the physical characteristics of Catahoulas are somewhat varied. The tail of the Catahoula may be long and whip-like, reaching past the hocks of the back legs, or else bobtail, which is a tail that ranges from one vertebra shorter than full length to only one vertebra in total length. The question mark tail is a common tail trait, often with a white tip. The bobtail is a rare but natural part of the Catahoula heritage.