The dragonfly is an insect animal of the genus Odonata. Dragonfly has well-developed wings, and the base of hindwing is slightly larger than the base of forewing. At rest, the four wings are spread out and laid flat on both sides. The head is flexible and has short antennae. The compound eye is well-developed, with three monocular eyes and powerful chewing mouthparts. The abdomen is slender, with thin and weak feet and hooked thorns. The larvae are short and thick, with rectal gills and tailless. Dragonfly is a typical incomplete metamorphosis insects, but also the eyes of the most insects. "Compendium of Materia Medica" contains: "Dragonfly, said its tail green also; Wing rainbow, said its shape alone also, or cloud its tail as nails also, or cloud its tail good high and upright. Therefore, it is called, flying, and flying."