Mark Hamill might be best known for his deep connections to the Star Wars galaxy, but he's also forged a highly successful career as a voice-over performer. And while he's had the chance to blend the two in the past (see Hamill's tweet lower down the page), The Mandalorian's Jon Favreau revealed in the final episode of making-of series Disney Gallery: The Mandalorian that Hamill voiced a droid in an episode of the show's first season.
An uncredited Hamill was the voice behind EV-9D9, who served as a bartender at Chalmun's Mos Eisley cantina on Tatooine, and was previously employed bossing other robotic types around on Jabba's barge in Return Of The Jedi (where he was then voiced by the film's director, Richard Marquand).
Hamill may well pop up again in some form next season, but we may not know what it is until someone flags it up. Still, we know we'll be listening out for his tones when the show returns to Disney+ in October.