Poi and Ping were identical twin brothers that lived in Makapu Village. They wore their hair and clothing in such a way as to look like mirror images of each other; Poi wore his braid on the ornate pad of his robe on the left shoulder while his twin wore it on the right shoulder. There were only a few characteristics that distinguished the brothers from each other, the most notable being the fact that Poi was an earthbender while Ping was not, proving that bending abilities are not solely defined by genetics. As with some other earthbenders, Poi did not wear shoes so he could be closer to the earth.
During the village's ceremonial cloud-reading in which the local fortuneteller, Aunt Wu, made predictions based on cloud formations; one such prediction was that twins would enjoy a good year. Poi and Ping cheered and "high-fived" each other. Shortly before the volcanic eruption of Mt. Makapu, Poi was part of a small group of earthbenders tasked with creating an earth trench to contain the molten lava that would eventually spill out of the volcano.