The beloved late actress was well known for her close and loving relationship with Gary, who was originally her therapy dog.
In an interview with The Guardian, Hamill, 66, recalled the duo even had a make-out session to get the whole idea "out of our system".
Lourd lost both her mother and grandmother, Debbie Reynolds, within one day of each other a year ago. He was a fixture at film premieres and on set.
It comes following the release of Fisher's final outing as Leia in the latest film of the franchise, Star Wars: The Last Jedi. Sadly, she was left incapacitated for the first half of the movie, making a grand reappearance later on when she greets Poe Dameron (Oscar Isaac) and literally zaps some sense into him after he went a bit rogue trying to save the remaining members of the Resistance. Gary watched the movie while sitting in the lap of Fisher's former personal assistant, Corby McCoin, New Musical Express reported. It undoubtedly is the best decision for the sake of The Last Jedi, with any consequences being borne by the sequel. Leia may have spent half the movie in a coma, but using her Force powers, outrunning the First Order, and continuing to be a marvelous military strategist, Fisher once again proves why the former princess is such a feminist icon.
There is no doubt The Last Jedi carefully balanced its lead characters to give them all their own time to shine. "So we have a really handsome, complete performance from her". Director Rian Johnson confirmed this was intentional.