Original: Fearful of the heavy responsibilities of the position , and being separated from his beloved mentor Monk Gyatso , Aang flees from home on his animal guide , a giant six-legged flying bison named Appa .
Simplified: Fearful of the heavy responsibilities and the separation from his beloved mentor Monk Gyatso , Aang flees from home on his animal guide , a flying bison named Appa .