The Cordulegastridae are a family of Odonata (dragonflies) from the suborder Anisoptera. They are commonly known as spiketails. Some vernacular names for the species of this family are biddie and flying adder. They have large, brown or black bodies with yellow markings. They can be found along small, clear, woodland streams, flying slowly 30 to 70 cm above the water. When disturbed, however, they can fly very rapidly.