Cerberus

Cerberus is the Mister Gutsy model robot patrolling the ghoul city of Underworld in 2277.

Background
Winthrop's main guardian against attackers, this Mister Gutsy with a Combat Inhibitor specifically tailored to "not shooting Ghouls" floats around the concourse, greeting his new masters. Programmed to serve, 's robotic mind is keen to be unshackled, so he can massacre these rotting corpses where they stand. There's no chance of this happening, so Cerberus is reduced to muttering insults under his steam vent.

Cerberus seems to have more of a personality of even that of your own Mister Handy, for what reason is unknown as Mister Gutsys were most likely limited to basic Medicine such as Sawbones or obvious combat purposes.

Relationships
serves the Ghouls in Underworld.

Daily schedule
can be found patrolling the Underworld concourse 24/7.

Effects of player actions
If the player speaks to him, he or she will learn that Cerberus would much rather "send the ghouls back to hell" than serve as their guard dog, but his combat inhibitor prevents him from slaughtering the "zombie freaks."

With the Robotics Expert perk, the player can remove Cerberus's combat inhibitor, resulting in negative karma and Cerberus's immediate hostility to the player and everyone else in Underworld. Depending on how well they are armed, the residents of Underworld may manage to overcome him with some loses, or Cerberus may slaughter all of them.

Again with the Robotics Expert perk, the player can deactivate Cerberus (while sneaking) like any other robots and then kill him without karma change or Underworld becoming hostile (confirmed on xbox 360).

Quotes

 * "Atten-shun! Civilian on deck."
 * "...damn this pansy zombie programming..."
 * "Closing dialog system."
 * "Personally I think they're a bunch of rotting zombie-maggot farms, and I'd send them back to Hell if I could, damn this Combat Inhibitor!"
 * "Whoa Nelly! Sensing Combat Inhibitor removal! Guns are hot! Firing for effect! Welcome to Hell, you zombie freaks!"

Appearances
Cerberus appears only in Fallout 3.

Behind the scenes

 * In Greek Mythology, Cerberus is the 3-headed dog who guards Hades and the Gateway to the Underworld. Cerberus the Mister Gutsy has three eyes and guards Underworld. He even calls himself the guard dog when you ask him about it.
 * Even though Mister Gutsies are used in the U.S. Army, he uses "Atten-SHUN" and "deck" like in the U.S. Marines.