A juvenile male stag beetle with the scientific name Aegus chelifer chelifer, and in Thai called duang kihm rong kao. It is overall black, with small grooves along the length of its elytra (the shield-like wing caps) and large, distinctive, mandibles, positioned horizontally. Its head and pronotum (the dorsal front part of the thorax) have tiny indentations that, due to light, may look somewhat like silvery spots.