The Grim Muscari has a curved, grey handle with a small, blue section near its base and a flat, khaki-colored pommel. The blade is thin and elegantly designed. The top of its main blade is smooth, blue, and curves downward slightly, while its underside is khaki-colored and ridged. Its back blade is comprised of four blue, thin blades that curve upward slightly. The shaft of the blade is mainly blue, but sports a small, khaki-colored spike decorating its base, and a ring of the same color going around its top.
Muscari is an odd genus of flowers commonly known as "grape hyacinths" because of their shape and color, often a deep blue like the Grim Muscari's blade. Hyacinth flowers, though unrelated to the Muscari genus, were said to have grown from the blood of Hyacinthus, a young boy in Greek mythology that was killed by the god of the west wind. "Grim" can mean "gloomy", "sinister", or "rigid". The Western personification of death, the Grim Reaper, is frequently depicted carrying a scythe.
Grim Muscari has a ground combo that is similar to many of Marluxia's other scythes. It is a swing to the left, then right, and upward slash, and a slice down at the ground. The aerial combo consists of a swing to the left, then back to the right. Marluxia then continues the combo by tossing the scythe into the air, catching it Marluxia does a 360 slice.