While he may have only appeared briefly in The Force Awakens, he more than made up for it in The Last Jedi as Mark Hamill reveals that he was not only the man behind the voice but also the motion capture of Canto Bight character Dobbu Scay.
Posting on his personal Twitter account, Hamill responded to a fan’s question regarding the Dobbu Scay character and the scenes on Canto Bight. Stating that they couldn’t help but laugh when they watched the admittedly humorous moment, a fan named Kirin was curious whether the actor had worn a motion suit for the scene? Hamill confirmed that he had indeed. Noting the common (and widely misreported) misconception that he only provided the voice, he revealed that he filmed the scene in a full-motion capture suit. He also detailed the process, which included a giant-sized medicine ball that served as a stand-in for BB-8.
It is commonly (& mistakenly) reported that I only did the voice of Dobbu Scay, but I filmed the scene in a full motion-capture suit w/ a giant-sized medicine ball to make me the same size as BB-8. I didn’t expect to be credited, assuming it would be another unbilled easter-egg. https://t.co/f6hAPOstxR
— Mark Hamill (@HamillHimself) 29 June 2019
Now we have to wonder if he played other characters in The Rise of Skywalker.