D-756 was a Tellarite merchant ship owned by bounty hunter Tevrin Krit in the late 2250s.
Sometime after Harcourt Fenton Mudd's departure from the USS Discovery in 2256, Krit's ship rendezvoused with a female bounty hunter to purchase Mudd from her. He then set a course for the USS De Milo to deliver Mudd for a Starfleet payout, unaware that the Mudd in his custody was actually an android duplicate sold to him by the real Mudd in disguise. (ST: "The Escape Artist")