KL-E-0

KL-E-0 (or Kleo) is a friendly Assaultron merchant in Goodneighbor

Background
KL-E-0 is an Assaultron that resides in Goodneighbor and acts as a merchant. She owns the store Kill or Be Killed, which is located directly next to Daisy's Discounts. She sells Partystarter, a unique missile launcher.

If KL-E-0's terminal is hacked, it is revealed that she has a plan to kill several members of the Goodneighbor community, if the need arises. Her plan to eliminate the Neighborhood Watch is to wait for a super mutant or raider attack, planting high explosives at key areas of the defensive perimeter, and post-detonation, relocating immediately due to Goodneighbor's vulnerability.

KL-E-0 has a contingency plan in case her original plan fails: She understands that collateral damage may be possible but considers losses acceptable without too much disruption to her business.
 * Shoot Daisy with a laser from long range, as she is too close to Kill or Be Killed to outright assault her without raising suspicion.
 * Sneak into Bobbi No-Nose's hideout at night, dismantle the lights and then kill the occupants one by one.
 * Pay one of Whitechapel Charlie's associates to do the dirty work for her.
 * Eliminate Fahrenheit first by strangling her in her sleep, and lace all of the chems within the Old State House with poison to take out John Hancock.

KL-E-0 seems to hold a certain amount of respect for Magnolia, considering her a fellow working girl and willing to give her a chance before sudden termination. Her contingency consists of burning down The Third Rail as a warning. Should she resist after that, a simple clean shot to the head would be the outcome.

Other interactions
The Robotics Expert perk allows hacking into her system and turning her into a normal Assaultron. It will suspend her trading function temporarily and can return to a normal trader after choosing shutdown/activate while she is still following the player around in Goodneighbor.

Quotes

 * "Everything here is guaranteed to injure, maim, or kill at your discretion. Except me. I only kill when I want to."
 * "I'm a woman, baby. Can't you tell?"
 * "Runtime Conclusion: Why work for the man, when you can work for yourself?"
 * "New Designation: K-L-E-0 'Kleo'. Fully independent small business owner."
 * "But as far as I'm concerned, I'm a woman. And I run a store that sells very large guns."
 * "Anything that can kill a man, I sell. Except suicidal depression. That is unfortunately not packageable."
 * "Come back when you're ready to go all the way."
 * "I've got a weapon for every situation. Hunting, protection, cold blooded murder, HOT blooded murder."
 * "Purchase a variety in case of boredom."
 * "Don't worry, I only test the weapons on customers I don't like."
 * "Each weapon tested on someone who deserved it."
 * "I have a pistol on sale, soaked in the blood of the last person who asked me that."
 * "Are you going to buy something or do I have to incinerate you?"
 * "Murder and mayhem at a discount."
 * "A gun for every occasion, purchase a variety in case of boredom."
 * "Fine, I'll add you to my 'Kill Eventually' list."
 * "Can I interest you in my arsenal of death, destruction and disintegration?"
 * "Weapons to solve any problem."

Appearances
KL-E-0 appears only in Fallout 4.

Behind the scenes
Her terminal is titled "Have a Plan to Kill Everyone You Meet," which is a reference to the Major General James Mattis quote, "Be polite, be professional, but have a plan to kill everybody you meet."