Bear Necessities

Bear Necessities is an unmarked quest

Detailed walkthrough
Talk to Lindsay, a Mini Boomer at Nellis Air Force Base, and she will ask the Courier to help find her missing teddy bear. In the hangar, where Loyal and Jack work, there will be a large circle of crates in the middle of the room. Walk around these and look through between them until Mister Cuddles is found.

Take the bear back to Lindsay in the children's barracks or schoolhouse and speak to her. Returning the bear to Lindsay will gain Boomers fame. Conversely, with a 60 Speech check, the player character can lie and tell Lindsay that Mister Cuddles is dead. She will run away crying, resulting in Boomers infamy and negative Karma.

Behind the scenes
The name of the quest "Bear Necessities" is a reference to the Disney song, "The Bare Necessities," performed in the film The Jungle Book.

Bugs
Even after giving Mister Cuddles to Lindsay, she will still greet the Courier asking if they have found the bear; this allows the quest to be completed both ways, so one can get the XP and not lose/gain any fame.