Large and very distinctive rodent. Un­mistakable. Thickset with coarse blackish brown fur with thick bristles on neck, shoulders, and legs, thinner ones on head. Along center of head along neck to back, a mane of long, brownish white hairs, paler toward tip, that can be erected to form a crest. From middle of back, along hind flanks and upper side of tail, there is a crest of black-and-white quills, reaching up to 40cm in length. Quills at end of tail white, short, and hollow. Head large and blunt, with small eyes and ears. Head yellow-gray in color. Legs stout with large pads and powerful claws. Voice confined to grunts, but can also rattle the tail quills.