Brian Tochi

He is the only actor to appear in Star Trek (1966) as a child and Star Trek: The Next Generation (1987) as an adult.

You come in, you sit down, they give you the script, you look for your parts and you run through it. You make changes, then you tape it. Real easy! You don't have to worry how you look, you don't have to shower, you don't have to do anything if you don't want to. (on doing voiceover work)