Gil Headstrong is an astronaut from The Mask: The Animated Series. He only appeared in the season 2 episode, For All Mask-Kind. He is a beloved, famous astronaut for the Edge City space program who is secretly paranoid of aliens. He was partnered up with Stanley Ipkiss as the first "average person" astronaut in his latest mission into space where he dealt with The Mask's troublesome antics and real-live aliens.
Headstrong is a skilled and talented astronaut, but extremely paranoid about aliens, usually "little green men." His many missions into space was possibly the reason for his paranoia in the first place.
He is egotistical and self-centered as he hates it when other people, like Stanley, stand in the way of the spotlight and people cheering for him. He pushes Stanley away to be in front of the people's attention. He is selfish also as when Headstrong was doing his star-date log (parodying Captain James T. Kirk's from Star Trek) about the mission after launching The Mask into space when mistaking him for an alien, he believes that Stanley is dead after dealing with the "alien" and in a grinning manner, says his final honorable words about him, "Better him than me."
- His name parodies the late American astronaut, Neil Armstrong, the first human being to land on the Moon. The title of the episode he appeared in references his famous quote, "That's one small step for (a) man, one giant leap for mankind."
- Headstrong had a running gag of mispronouncing Stanley's last name as Buttkiss. Which Stanley keeps trying to correct him on.