The full PG makeup took many hours to apply, often requiring Matthew Ninaber to be the first person to arrive for shooting and the last to leave. He spent so much time in the costume that the crew failed to recognize him without it.
Psycho Gorman is from the planet Gigax, which is most likely a reference to one of the creators of Dungeons & Dragons, E. Gary Gygax.
All the scenes with the kids were shot first, followed by shooting scenes with adults using stand-ins for the kids off screen.