William Shatner Used His 3rd Rock From The Sun Guest Spot To Pull One Over On French Stewart

As sitcom premises go, Bonnie and Terry Turner's ultra-popular sci-fi sitcom "3rd Rock from the Sun" is first rate. The show follows a quartet of nonhumanoid space aliens from a distant galaxy — played by John Lithgow, Kristen Johnson, French Stewart, and Joseph Gordon-Levitt — who have disguised themselves as a human family in order to study our species up close. The show's comedy is derived from their utter cluelessness about the way the people in Ohio behave. "3rd Rock from the Sun" came in a long tradition of silly sci-fi sitcoms that included "Out of the World," "ALF," "Aliens in the Family," and "They Came from Outer Space." These were shows that took familiar American sitcom tropes, and skewered them by putting aliens in place of traditionally human characters. 

The central aliens on the program would regularly report back to an ineffable, off-screen supreme alien lord that was only ever referred to as the "Big Giant Head." For several seasons, the Big Giant Head would communicate via psychic waves that took over the body of Harry, that character played by French Stewart. The Big Giant Head would finally manifest itself as a human in the fourth season two-part episode "Dick's Big Giant Headache" (May 25, 1999). The Big Giant Head was, in a fun piece of casting, played by none other than "Star Trek" star William Shatner. 

The Big Giant Head arrived by plane, and the immediate exchange between Shatner and Lithgow might be one of the funniest in-jokes in sitcom history. 

The joke is as follows: 

The drunken Shatner stumbles off the plane, unused to having a human body. He complains that the flight was scary, as he saw something alive on the wing of the plane. This is a cute reference to the episode of "The Twilight Zone" called "Terror at 20,000 Feet" (October 11, 1963), wherein Shatner played a man who did indeed see a gremlin lurking on the wing of a plane in flight. As a retort, John Lithgow pipes in with "The same thing happened to me!" Lithgow, of course, played Shatner's role in the feature film version of "Terror at 20,000 Feet" included in 1983's "Twilight Zone: The Movie." TV historians take note.

Shatner's presence on the show was something of a coup for the "3rd Rock" crew. Although the show already featured an established star in Lithgow, and the rest of the cast would be all household named by the end of the show's successful six-season run, a guest spot from a geek icon like Shatner threw the cast into a flight of nerves. This, from a show that also featured celebrity guest spots from the likes of Elvis Costello, Billy Connelly, and Christine Baranski. In a 2021 "3rd Rock" cast reunion, written up in Vulture, French Stewart revealed that the cast's — or rather his — nervousness left him gullibly open to a prank staged by Lithgow and Shatner. 

Stewart recalls a time when he was deliberately put on the spot. When he arrived on set, Shatner and Lithgow had orchestrated an argument of some kind. While the two actors bickered over a detail in the script — and Stewart doesn't elucidate on the scene or the line in question, only that there was an argument — Stewart was invited to come arbitrate, essentially forcing him to side with his longtime co-star or a visiting guest celebrity. It almost seemed like some sort of twisted psychological study. In Stewart's words:

"I sit down. Then it starts getting a little more heated. And I'd never seen this from John. He's such a nice man — it never happens. And then it's getting really heated. And then finally Shatner looks at me and says, 'Well what about you? How do you think the scene should be done?' And I know I'm going to see John every day, and Shatner will be gone on Monday. So I go, 'Well, I think John's way is the best way.' And then they both just start laughing at me — and I realize it's April Fools' Day!"

Stewart then acknowledged that the one-week shoot with Shatner was, moving forward, going to be tainted by his decision. After all, he decided to throw Shatner under the bus in favor of his friend. Lithgow might be flattered, however, that Stewart had the integrity to stand up for a co-star, and to William Shatner, no less. 

There didn't seem to be hard feelings on Shatner's part, at any rate. Shatner returned as the Big Giant Head in three additional "3rd Rock" episodes in its fifth season.