A Stargate SG-1 Episode Features A Cameo From A Major Simpsons Star

After Roland Emmerich made a movie back in 1994 about a team of explorers who travel to distant worlds, it's not all that surprising that plans for a "Stargate" trilogy were scrapped — despite the fact the film itself did quite well at the box office. That is to say, you can see how such a premise would lend itself to a serialized form of storytelling, with new alien worlds and races being discovered in each episode. That does, of course, throw up a few issues, like suddenly requiring a wide array of actors to play those alien races.

As such "Stargate SG-1" featured all manner of guest star, from multiple "Star Trek" actors to a future Marvel Cinematic Universe fan-favorite in the form of Yondu Udonta actor Michael Rooker. "SG-1" even featured a cameo from a "Star Wars" legend, but there was one guest appearance which likely went overlooked by many viewers back in 2005. The great Dan Castellaneta, who since 1989 has been the voice of Homer Simpson (longer if you count the comedy sketch show that quietly launched "The Simpsons"), appeared in a season 8 episode of "Stargate SG-1." He played Joe Spencer, a man who has unwillingly become an SG-1 super-nerd. But Castellaneta's appearance was a big moment for a series which had maintained a link with "The Simpsons" throughout its then eight-season run.

In "Stargate SG-1" season 8, episode 15, entitled "Citizen Joe," Dan Castellaneta plays a barber by the name of Joe Spencer. Seven years prior to the setting of the episode itself, Joe bought a mysterious black stone from a garage sale and ever since has been seeing visions of the SG-1 team and their various exploits. Spencer soon starts writing down his visions as if they were stories of his own invention, selling them to magazines and ultimately becoming so obsessed with the SG-1 team that his wife leaves him and his life falls apart. This leads him to track down Richard Dean Anderson's Colonel Jack O'Neill, holding the SG-1 leader at gunpoint and accusing him of ruining his life.

When we first see Joe in this setting, he simply appears to be about as big a "Stargate SG-1" nerd as Comic Book Guy from "The Simpsons," at one point listing his extensive knowledge of Jack O'Neill. "You're Brigadier General Jack O'Neill," he says, "head of Stargate command at Cheyenne Mountain. You used to command SG-1 which is now led by Lieutenant Colonel Samantha Carter [...] You have a thing for 'The Simpsons,' fishing, Mary Steenburgen, the color Peridot, and you're a terrible ping pong player."

The reference to "The Simpsons" here isn't just a casual Easter egg for fans who know Castellaneta as the voice of Homer Simpson. Anderson's character in Stargate SG-1, Jack O'Neill, is a big fan of the show and at numerous points throughout the series has spoken about his love for the long-running animated comedy (which became the longest-running primetime scripted series back in 2018), often recording episodes and quoting Homer's famous "d'oh" catchphrase. He's compared the big villains of "SG-1," the Goa'uld, to the nefarious nuclear power plant owner Montgomery Burns of "The Simpsons." In the season 8 episode "Moebius, Part 1," an alternate version of O'Neill is even revealed to own a boat called "Homer." As such, Castellaneta's appearance here is a big moment for the two series, and including a nod to O'Neill's longtime love for "The Simpsons" is a nice way to acknowledge the link.

As "Citizen Joe" plays out, it's revealed that Joe Spencer actually bought an ancient long-range communication stone from the planet P3R-233. When activated, this stone melded Joe's mind with O'Neill's, whose thoughts were transmitted to Joe over the course of the prior seven years. By the end of the episode, O'Neill takes it upon himself to help Joe get his old life back, talking to his wife and helping put the pieces back together.

The rest of the episode is mostly a clip show, with Joe's visions acting as a way for "SG-1" to revisit moments from the previous seasons. But having Castellaneta appear made it a significant installment considering the long-standing link between "The Simpsons" and "SG-1." It was also fitting for Joe and O'Neill's minds to be linked, seeing as the latter was such a "Simpsons" fan and by that point Richard Dean Anderson had already started to leave "Stargate SG-1," reducing his time on the series and eventually leaving altogether. Having Anderson and Castellaneta appear together prior to the former's departure felt like something that needed to happen.

Anderson actually ended up playing himself in a season 17 episode of "The Simpsons" just a year after "Citizen Joe" aired. Entitled "Kiss Kiss Bang Bangalore," the episode sees Anderson kidnapped by Patty and Selma for revealing that he never liked playing the lead character in "MacGyver," the two sisters' favorite show. He initially attends the pair's "MacGyver" convention while looking for the "SG-1" convention, confirming that the sci-fi series also exists within the world of "The Simpsons." The episode was also co-written by Dan Castellaneta.