Wondrous Item, very rare (requires attunement by a Monk, wizard, palidan, or fighter)
this backpack is a magic item that grows (or shrinks) to the size of its wearer
this bag can also hold 50 pounds of wieght without ripping or falling apart, 20 of those pounds put no strain on the bag or the person wearing it what - so - ever
Notes: Monk, wizard, palidan, or fighter, Utility, Container