|The following is based on Fallout Shelter or Fallout Shelter Online and some details might contradict canon.|
One of the children of the vault has had their teddy bear stolen by a "monster" while playing outside. The child now refuses to sleep without their teddy, and claims the monster hides under their bed. The player's dwellers can be sent out to track down and kill the beast.
This quest will lead the dwellers to a randomized building where they must make a final push to reach the monster. The top floor has a mole rat broodmother accompanied by two mole rats. Down the elevator, the second floor has a group of three mole rats in the rightmost room and two groups of three radroaches in the left two rooms. The third floor is clear of enemies. The fourth floor has two groups of three radroaches in both rooms. The fifth floor has a group of three radroaches in the leftmost room. The fifth floor has another group of three radroaches in the rightmost room. The bottom and final rooms have the "monster," which is an alpha deathclaw accompanied by two more deathclaws. Upon defeat, the alpha deathclaw drops a teddy bear as a reward. There is also a pickaxe and a random rare outfit in the room.