Thrashers, like mockingbirds and catbirds, belong to the family Mimidae and have the long tail that is typical of this family. The brown thrasher is about 12 inches long and has a distinctive long, curved beak. The upper parts of the body are reddish brown and the breast is light-colored with heavy, dark streaks. Brown thrashers are mainly ground feeders, often using their long beaks to toss aside leaves as they search for food. They will sometimes catch prey by jumping up in the air, however. Their food consists mainly of insects, lizards, frogs, snakes and berries. These birds are usually shy, but can become very aggressive when defending their young, often charging towards the head of an intruder.

Male birds sing loudly from prominent perches in order to attract females in spring. A receptive female responds by picking up a twig and hopping towards the male while chirping and fluttering her wings. The male has the largest documented song repertoire among north American birds, with over 1,100 song types which include mimicry and improvisation. A thrasher will usually repeat a phrase twice. As a general rule, catbirds repeat a phrase once, and mocking birds repeat it several times.