Oasis (quest)

 is a Fallout 3 quest. It is also an Xbox 360 achievement.

Objectives and walkthrough
Harold, a special FEV mutant with a tree on his head which he called Bob, eventually found himself overwhelmed by it and became rooted to the ground during his travels in the Capital Wasteland region. Here he was discovered by several people who began to worship him as a god, and a small and exclusive cult known as the Treeminders began to form in secrecy. Bob began to blossom and many plants grew in this area, which became green with life, a stark contrast to the outer wasteland.

Harold reveals his true identity, and begs for mercy; after being stuck in the same position for decades he is eager for death. The other dwellers of "Oasis" have ignored Harold's wishes so far, and ask you to instead either suppress or expand Harold/Bob's fertility.