Immature fruit bodies of L. mokusin are white, gelatinous "eggs" measuring 1–3 cm (0.4–1.2 in) in diameter, and are attached to the ground by thickened strands of mycelium called rhizomorphs.
As the fungus matures, the egg ruptures as the fruit body rapidly expands, leaving volval remnants behind at the base.
The stipe of the hollow, spongy mature fruiting body has dimensions of 10–15 cm (3.9–5.9 in) by 1.5–2.5 cm (0.6–1.0 in), and ranges in color from white to pink to red, with 4–6 distinct deeply grooved sides divided lengthwise by ribs.
The basis of distinction between L. mokusin and other species of Lysurus is the angular form of its stipe.
The sides branch out into 4–6 arms that are fused together at the tip to form a pointed apex, resembling a spire.
As the mushroom matures, the arms may spread apart.
The outer surface of the arms is coated by a brownish, slimy, foul-smelling spore mass called the gleba; its fetid odor helps it attract flies and other insects to assist in spore dispersal.
The odor has been compared to "fresh dog feces", "rotting flesh" or sewage.

The spores are cylindrical in shape, smooth, thin-walled, and hyaline (translucent), with dimensions of 4–6 by 2–2.5 µm.
Scanning electron microscopy reveals that one end of the spores has a hilar scar—an indentation in the spore wall that results during its separation from the sterigma of the basidium.
The basidia (spore-bearing cells) are usually eight-spored, and the gleba composed of chains of roughly spherical, fusiform, ellipsoid to broadly club-shaped cells that are either 6.5–7.4 by 2.8–5.6 µm or 37.1–46.3 by 18–28 µm and also mixed with filamentous cells 2.3–4.5 µm wide.
The hyphae of L. mokusin have clamp connections.
Immature fruit bodies of L. mokusin are white, gelatinous "eggs" measuring 1–3 cm (0.4–1.2 in) in diameter, and are attached to the ground by thickened strands of mycelium called rhizomorphs. As the fungus matures, the egg ruptures as the fruit body rapidly expands, leaving volval remnants behind at the base. The stipe of the hollow, spongy mature fruiting body has dimensions of 10–15 cm (3.9–5.9 in) by 1.5–2.5 cm (0.6–1.0 in), and ranges in color from white to pink to red, with 4–6 distinct deeply grooved sides divided lengthwise by ribs. The basis of distinction between L. mokusin and other species of Lysurus is the angular form of its stipe. The sides branch out into 4–6 arms that are fused together at the tip to form a pointed apex, resembling a spire. As the mushroom matures, the arms may spread apart. The outer surface of the arms is coated by a brownish, slimy, foul-smelling spore mass called the gleba; its fetid odor helps it attract flies and other insects to assist in spore dispersal. The odor has been compared to "fresh dog feces", "rotting flesh" or sewage.
The spores are cylindrical in shape, smooth, thin-walled, and hyaline (translucent), with dimensions of 4–6 by 2–2.5 µm. Scanning electron microscopy reveals that one end of the spores has a hilar scar—an indentation in the spore wall that results during its separation from the sterigma of the basidium. The basidia (spore-bearing cells) are usually eight-spored, and the gleba composed of chains of roughly spherical, fusiform, ellipsoid to broadly club-shaped cells that are either 6.5–7.4 by 2.8–5.6 µm or 37.1–46.3 by 18–28 µm and also mixed with filamentous cells 2.3–4.5 µm wide. The hyphae of L. mokusin have clamp connections.
Lysurus mokusin