- "Emtrey, if I recall his introductory monologue, is supposed to know the rules, regs, and procedures of over six million military organizations past and present."
- ―Wedge Antilles
M-3PO, also known as Emtreypio or Emtrey, was a black military protocol droid of the 3PO series, that served in Rogue Squadron as its quartermaster. Cobbled together from parts of other protocol droids, he served the Rogues from their reformation in 6 ABY through to the Yuuzhan Vong War. Because of his improvised nature, he had a protocol droid's body, but had the head of a Spaceport control droid.
Emtrey was built on Hoth by a Rebel lieutenant named Losca for the purpose of procuring goods. He had special programming to assist with that purpose: a 'scrounger mode' activated when hounded about acquiring parts. He also had a strange program that disabled his normal personality and functions when told to shut up more than three times. This program essentially turned him into a 'dumb' terminal with access to Emtrey's memory banks. Both of these features were used by Rogue Squadron members during the time he served with them. After the New Republic took Coruscant for the first time, this terminal mode was disabled.
It was later revealed that the terminal mode was actually built into Emtrey by New Republic Intelligence in order to discover if then Captain Tycho Celchu had been successfully brain washed into an Imperial Agent. Emtrey was given this and other programming that made him into a very valuable tool for a spy, which would have exposed Celchu if he was a spy if Celchu used him in that manner. Emtrey was also able to provide proof that Celchu had not met with Imperial agents as Corran Horn accused him of doing. Horn's reappearance, followed by the betrayal of Imperial mole Erisi Dlarit made Celchu's innocence obvious. The special programming was removed during the trial, and Corran Horn realized that he had been assigned to monitor Celchu when the remote mode would not work any longer
After Celchu's trial, and the departure of Ysanne Isard for Thyferra, Rogue Squadron members resigned to topple the puppet regime she had set up on that planet. Emtrey, along with all the squadron's equipment and fighters was surplussed out by someone in the military as a way of giving back door support to the former members of Rogue Squadron. Emtrey was acquired by the former Rogues, and he served in a variety of capacities with them. He was later named liaison on board the Valiant, a droid ship that survived the destruction of Alderaan.
Once Isard was defeated, Emtrey returned to service with the New Republic.
- X-Wing: Rogue Squadron (First appearance)
- X-Wing: Wedge's Gamble
- X-Wing: The Krytos Trap
- X-Wing: The Bacta War
- X-Wing: Solo Command (Mentioned only)
- X-Wing: Isard's Revenge
- I, Jedi
- The New Jedi Order: Dark Tide II: Ruin
- The Essential Guide to Droids
- A Guide to the Star Wars Universe, Third Edition, Revised and Expanded
- "Who's Who in Echo Base"—Star Wars Insider 74
- The Complete Star Wars Encyclopedia
- Star Wars: The Official Starships & Vehicles Collection 29