Mark Hamill was 46 in Scooby-Doo on Zombie Island when he played the character 'Snakebite Scruggs (voice)'.
That was over 26 years ago in 1998.
Today he is 72, and has starred in 158 movies in total, 106 of those since Scooby-Doo on Zombie Island was released.
In Scooby-Doo on Zombie Island, I think Mark Hamill looks: