The Brain (Point Lookout)

 was one of the inhabitants of Point Lookout and a member of the prestigious Calvert family before the Great War. He survived the war by preserving his brain in a jar. This has allowed him to survive for over 200 years and develop psychic powers. He communicates with the outside world as a hologram and is worshiped like a god by a local tribal cult. He uses this for his purposes, however the cult, due to their religious fervor, frequently misunderstand him leaving him very frustrated. He enlists the PC to help him kill his arch rival Desmond. He speaks in a rapid-fire voice and tends to refer to himself in the third person. He is a nod towards the Calculator, being a brain in a machine under a vault.

Bugs

 * There is a common glitch where the player will randomly be informed that The Brain is unconscious whenever they go near the boardwalk. This is because Proffersor Calvert's actual actor, named The Brain, resides in an unopenable Pulowski Preservation Shelter hidden in the soda shop neighbouring the The Homestead Motel, and is possibly falling through the map and being knocked out due to falling damage.
 * If you go to the area around the Ferris Wheel you will notice a green dot on the radar to the right of the ferris wheel, indicating a friendly NPC, The Brain. He can be reached by the player although no conversation may be started with him and he has the cloak effect similar to that given by a Stealth Boy. The following is how to reach The Brain:
 * On the 360 and PS3 versions of the game this area is is reachable by use of stacked baby carriages, or jumping from the truck on the opposite side of House of Wares to the rooftops and jumping rooftops till you get there. Upon getting on and falling through the roof, you can find this hidden occupied Pulowski Preservation Shelter with The Brain in it. However, it cannot be opened.  It is most likely here for when he talks to you during the quest Thought Control.
 * PC players can simply use the command to travel through the walls and reach the Pulowski Preservation Shelter with The Brain inside.

Trivia
The French movie "The City of Lost Children" features a professor named Krank who lives in a far-away lighthouse. He orders his minions to kidnap children, so that he can steal their dreams. His arch-nemesis is a professor named Irvin, who appears as a human brain in a bubbling water tank.

Appearances
appears only in the Fallout 3 add-on Point Lookout.