6 Famous Actors You May Not Have Realized Were Guest Stars On Star Trek: Voyager

"Star Trek: Voyager" debuted on January 16, 1995, and was the first series on a brand-new Paramount-owned network, the UPN. Like the network, "Voyager" struggled quite a bit, famously floundering in the ratings and unable to secure the kind of cultural cache held by "Star Trek: The Next Generation," a series that had gone off the air in 1994. The premise was promising enough: a brand-new, super-advanced Starfleet vessel, the U.S.S. Voyager, was whisked clear across the galaxy by an ultra-powerful alien being searching for a mate. When the alien died, the Voyager was stranded in the Delta Quadrant, some 75 years away from Earth. Captain Janeway (Kate Mulgrew) would guide her crew back home, using limited resources and unable to call Earth for backup.

Initially, the reaction was merely warm, with Trekkies focusing more attention on the contemporaneous episodes of "Star Trek: Deep Space Nine." In early seasons, the "Voyager" showrunners tried to goose up ratings by including bikini beach segments, said to be a vital program on the ship's holodeck. It wouldn't be until the start of the show's fourth season that the character Seven of Nine (Jeri Ryan) was introduced. Dressed in a corset and a skintight catsuit, the former Borg character added a cheesecake element — as well as an android-like attitude — that viewers took to immediately. The series subsequently rearranged itself to be more about Seven.

Throughout, "Voyager" attracted numerous established stars to play bit parts on the show, including a few celebrities that only Trekkies would readily be able to tell you about. Indeed, on two occasions, known comedians played cool, terrifying villains on "Voyager." Oh yes, and a famous wrestler appeared before his big break in "The Mummy Returns."

Michael McKean as The Clown in 'The Thaw'

Actor Michael McKean started his professional career working in a comedy troupe called The Credibility Gap, which he ran with Harry Shearer, back in the 1970s when he was fresh out of college. His big break came in 1976 playing the role of Lenny in the hit sitcom "Laverne & Shirley." His star rose further with his appearance in the celebrated mock-rockumentary "This is Spinal Tap" in 1984. He appeared in "D.A.R.Y.L." and "Clue" the following year, more or less cementing his reputation as a comedy genius. McKean has been working steadily ever since and has dozens of credits to his name. He was just in "Weird: The Al Yankovic Story."

In "The Thaw" (April 29, 1996), the U.S.S. Voyager finds a distant planet where several people have been cryogenically frozen and their brains have been wired into a complex virtual reality system. When the crew of the Voyager enters the VR system to investigate, they find that the people's fears have manifested into a scary clown figure with no name. For years, the fear clown has been virtually torturing his creators, cackling with glee when they scream in terror. Soon, the Voyager crew finds they cannot escape the simulation until they solve a strange philosophical riddle: what does Fear want from us?

McKean gives a chilling performance as the Clown in what might be the best "Voyager" episode. It's strange in a way the show rarely dared to be.

Sarah Silverman as Rain Robinson and Ed Begley, Jr. as Henry Starling in 'Future's End'

"Star Trek: Voyager," as mentioned, debuted in 1995, which presented a continuity problem. Within the original mythos of "Star Trek," you see, the violent Eugenics Wars broke out in 1997, leading to an extended period of devastation. It wouldn't be until Earth was recovering from those wars that it would be able to start building the technological utopia that Gene Roddenberry dreamed about. Making a "Star Trek" show in 1996, then, had to address or undo that. Hence the two-part episode "Future's End" (November 6 and 13, 1996), which saw the Voyager traveling back to Earth in the year 1996 to do battle with, essentially, Bill Gates.

The plot, very briefly: when a 29th-century time traveler attacks the Voyager, it unwittingly leads the ship through an unpredictable time hole. The time traveler lands in 1967, at which point Henry Starling (Ed Begley, Jr.) discovers his tech. It seems that Starling used 29th-century technology to start the computer revolution. The Voyager lands in 1996 on Earth; there, Starling has become a tech magnate with the eager young astronomer Rain (Sarah Silverman) in his employ. Because the timeline was altered, the 1997 Eugenics Wars have been handily delayed. Rain and Tom Paris (Robert Duncan McNeill) proceed to instigate a flirtatious romance while Starling attempts to salvage Voyager tech for more plunder.

Recall that there was a boom in internet use and computer technology in the mid-1990s, so "Voyager" was being topical when it posited that the Microsoft revolution was caused by the invasion of technology from the 29th century. The episode is only okay.

Jason Alexander as Kurros in 'Think Tank'

Jason Alexander had long been an outspoken Trekkie and yearned to appear in any "Star Trek" series. His dream came true for the episode "Think Tank" (March 31, 1999), in which he played a sinister alien named Kurros. Alexander has told an amusing story about filming "Think Tank." Evidently, his young son came to visit the set while he was in full alien makeup — he was given an outsize forehead and wild hair — and he exclaimed, "You look like snot."

"Think Tank" is about, well, a think tank of ultra-sophisticated aliens who use a specialized machine to communicate telepathically. The tank is led by Kurros, and they apply themselves to solving scientific problems while also pondering the mysteries of the universe. At first, the think tank is helpful and appealing, but it doesn't take very long for the Voyager crew to discover a sinister plan. It seems that Kurros had manipulated a team of bounty hunters to chase the Voyager into his care, where he would, of course, kidnap Seven of Nine and allow her to join the think tank. Naturally, the Voyager gives him the slip.

The idea of an alien think tank is a cool one for "Star Trek" and might have opened the door to "Gulliver's Travels" levels of satire, depicting intellectuals as morally bankrupt and/or absurdly distracted. Sadly, the episode gets bogged down in plot and, because it was the raison d'être of the show by 1999, unduly highlighted Seven of Nine.

Daniel Dae Kim as Gotana-Retz in 'Blink of an Eye'

"Blink of an Eye" (January 19, 2000) has a titillating sci-fi premise. The U.S.S. Voyager discovers a planet trapped in a bizarre time bubble. For every minute that passes on the Voyager, 58 days pass on the planet below. The Voyager is able to watch centuries pass in a matter of hours, witnessing the citizens develop technology equivalent to 20th-century Earth. The ship's holographic Doctor (Robert Picardo) visits the planet, staying with the citizens for three years, learning all about their culture. When he returns, only minutes have passed. From the perspective of the people below, the Voyager is a permanent fixture in their sky. Eventually, the people send astronauts into space to investigate.

One of the astronauts they encounter is a man named Gotana-Retz, played by a pre-"Lost" Daniel Dae Kim, already a busy actor in television and film. His body adjusts to the time difference, and he is shocked to learn this fixture he always saw in the sky is populated by intelligent beings. When he returns to his planet, his people wage war on the Voyager, which is easy to do since their technology advanced so quickly. By the end of the episode, Gotana-Retz is a very old man.

"Blink of an Eye" is a thematically important episode of "Voyager" since it illustrates the filthy bootprints Captain Janeway tended to leave all over the galaxy. The Voyager eventually made its way home, but, golly, it was awfully sloppy on the way. Sometimes, without even trying, the Voyager damaged the worlds it visited.

Dwayne 'The Rock' Johnson as Champion in 'Tsunkatse'

"Tsunkatse" (February 9, 2000) may be one of the more shameless episodes of "Star Trek: Voyager," which is saying something. While on shore leave, several Voyager officers discover a nearby mixed martial arts tournament called Tsunkatse. Shortly thereafter, they are kidnapped by a slimy character named Penk (Jeffrey Combs). Tuvok (Tim Russ) is injured, but Penk denies him treatment unless Seven of Nine fights in a Tsunkatse tournament. This is the same plot as any number of obscure 1980s martial arts pictures.

Naturally, Seven will have to fight the Tsunkatse champion, a character played by Dwayne Johnson back when he was only known as The Rock. Prior to "Voyager," Johnson had only had a small part on an episode of "That '70s Show" and on the short-lived TV version of "The Net." On "Voyager," he was essentially asked to play himself, complete with a wrestling ring, flashing lights, and a rock song entrance. His character didn't have a name, although his species was mentioned as Pendari, a species known to have a temper. His only dialogue is "Star Trek"-inflected kayfabe. "You're no bigger than a Tarkanian field mouse," he says.

"Tsunkatse" is a pretty risible episode, only notable for its cameo. If you ever wanted to see the diplomacy-forward, intellectual world of "Star Trek" overlap with the sweaty, demonstrative world of pro wrestling, then this is the episode for you. You're also one of maybe six people in the world.