Bus conductor (The Greatest Show in the Galaxy)

The Bus Conductor was an Android. It was disabled by the Seventh Doctor.

Later the Chief Clown forced Bellboy to fix him and they took the Conductor to the bus. Kingpin and Ace went to collect something from the bus and the Conductor tried to kill them, but at that point Kingpin had his memory back and he knew how to kill it.

Kingpin instructed Ace to press a button on his head. The Bus Conductor blew up. (DW: The Greatest Show in the Galaxy)