Masterslave disguised as a Klingon.
A masterslave was a type of robot in use by the Klingon Empire in the 23rd century.
History and specifics[]
Masterslaves were metallic, bipedal, humanoid-shaped automatons. In the 2260s decade, masterslaves were deployed to the Klingon outpost on Scaptar.
In the year 2265, when the mutinying crew of the starship Dorado approached Scaptar, Klingons offered to send a diplomatic envoy to meet with them. A transit-hopper did launch from the surface, but it carried a masterslave disguised as a delegate that carried deadly gas. Observing from afar as the envoy disembarked the transport in an EV suit, Captain James T. Kirk noticed something mechanical about the delegate's movements and warned Dorado. Mutineer Duncan closed the airlock hatch and sliced the robot in half. (TOS comic: "Mutiny on the Dorado")