The Morning Star has a black, spherical head with two beady, yellow eyes on it. It wears a conical, green helmet with an angular antenna attached to its tip. The majority of its body is encased in a spherical suit of armor with eight conical, black spikes spaced evenly over its surface. This armor is primarily colored in shades of green, with some yellow decorations on it. Its thin arms jut out of circular openings in the armor on either of its sides. Its spindly legs share a large, circular opening at the bottom of the armor, and the tips of its feet point upward. It can retract its arms and replace them with two large spheres covered in spikes, which it uses to beat enemies. The Morning Star has two Heartless emblems, on its front and another on its back, both of which are placed in the middle of a blue ring with a black background.
In Kingdom Hearts II Final Mix, the Morning Star's armor becomes blue with cyan, violet, and some yellow highlights on it. Its spikes are now silver, as opposed to the normal black.
The Morning Star's name refers to the melee weapon of the same name, which the Heartless resembles. Its second set of arms in particular are very similar to a morning star mace.