Dusk Bison resemble wild oxen. They have a large torso and head, huge horns, and comparatively small limbs.
In Grand Cross mobile game, two variants are introduced: one with yellow fur and thorny, upright horns; and one with brown fur and large hooked horns. They are notably more detailed than in the anime.
They are wild creatures who act as pests, attacking and destroying human farms, mainly at night and around dusk.
Nothing is known about these creatures' abilities, except that they are strong enough to destroy human farms.