Shirshu-spit darts are non-lethal darts used by the beetle-headed merchants living in the Si Wong Desert to temporarily paralyze victims. The preparation for the darts begins by harvesting the spit of a shirshu, which can paralyze most creatures, including a ten-ton flying bison, for up to an hour, depending on the dosage. The victim remains awake, but is paralyzed and incapable of movement.
After Appa was kidnapped by Ghashiun and his friends, the sandbenders sold the bison to some desert merchants. While completely tied down by the merchants, Appa heard Aang calling him with the bison whistle nearby. He tried to get away by shaking the transport trailer and flying away, which nearly succeeded. To stop him, one of the beetle-headed merchants pulled out a blow pipe and shot three shirshu-spit darts into one of his feet. The shirshu spit took effect immediately, and the escaping bison fell to the ground again, completely paralyzed.
- The trick lies in harvesting the wily shirshu's spit and in remembering to inhale before attempting to use the bamboo launcher, not during.