The skin is either rough and brownish gray or smooth and sparsely covered with short whitish gray to yellowish hairs. The underside of the body and inner sides of the legs are sometimes lighter than the rest of the body. Frequently, this whitish color extends along the sides of the upper lip. The skin usually hangs in loose folds.
Females have two pairs of mammae.
In most wild swine the tusks grow from the sides of the jaw. In Babyrousa, however, the upper tusks grow through the top of the muzzle and then curve backward toward the forehead. The upper tusks apparently have a general defensive function, and the daggerlike lower tusks are used offensively. Since the lowers are not honed by wearing against the uppers, however, the male actively sharpens them on trees. The wear pattern of upper tusks from Sulawesi indicates that these teeth are used to interlock and hold the opponent's lower tusks.