It emerges in what humans would consider a breech birth-tail first. In this position, there is no damage to the female. At birth, the cownose ray is about 11 to 18 inches in width. When mature, it attains a 45 inch width, may weigh 50 pounds or more, and is brown-backed with a whitish belly. This species does not have particularly distinctive coloration but its shape is readily recognizable.
Eyes peer out eerily from the side of the broad head.
Hidden within this strange head is a set of equally remarkable teeth plates designed for crushing clam and oyster shells. Being stung by a cownose ray, though potentially fatal, is uncommon. Unlike some other ray species, the cownose rarely rests on the bottom where a swimmer might step on its stinger. With pointed, recurved teeth lining its lateral edges, the spine processes toxins and mucous in its ventral grooves. Spongy venom glands which produce the toxin are situated along the underside of the spine.