When Aang arrived in the Spirit World seeking advice on how to defeat the Fire Nation that was attacking the Northern Water Tribe, he asked the baboon spirit for help, but the spirit wanted him to leave. Aang kept persisting for the cranky spirit to help him, but the baboon spirit only grew more agitated as he tried to continue his meditation. When Aang was still hanging around, the spirit told him to follow a ball of light and remarked, "Finally!" when he left. After losing the light, Aang was advised by Avatar Roku to see Koh, the Face Stealer. After Aang came back from his encounter with Koh, Hei Bai helped him return to the mortal world. The baboon spirit remarked, "Good riddance!" much to the annoyance of Hei Bai, who transformed into his monstrous form and struck the baboon spirit wi