Thopha saccata, commonly known as the double drummer, is the largest Australian species of cicada and reputedly the loudest insect in the world. Documented by the Danish zoologist Johan Christian Fabricius in 1803, it was the first described and named cicada native to Australia. Its common name comes from the large dark red-brown sac-like pockets that the adult male has on each side of its abdomen—the "double drums"—that are used to amplify the sound it produces.