Cyborg

The  is an NPC added in the 1.2 update. He only spawns once you defeat the Hard Mode boss Plantera and there is a house available for him.

Items
The Cyborg sells the following Items:

Trivia

 * Niner-7 is presumed to be a reference to the Star Trek Voyager character Seven of Nine
 * Fender is a possible reference to the Futurama character, Bender; "Fender Bender", a phrase reffering to a car crash.
 * T-3E0 might be a reference to the Star Wars character C-3P0.
 * A.N.D.Y. is possibly a reference to Andy the bomb, from RoosterTeeth's "Red VS Blue" Halo series.
 * Also tying in with this reference: the Greek alphabet was used to name the various A.I.'s of Project Freelancer, one of the main groups featured in RvB.
 * Niner-7 is also a possible reference to the RvB character Four Seven Niner
 * The quote "My expedition efficiency was critically reduced when a projectile impacted my locomotive actuator." might be a reference to The Elder Scrolls: Skyrim where the guards might say "I used to be an adventure like you, but then I took an arrow in the knee."
 * Kappa might be a reference to the Twitch.tv chat emote "Kappa".