The 5 essential Star Trek: The Animated Series episodes every Trek fan should watch

With the debut of Star Trek: Lower Decks, the Trek franchise is launching its second ongoing animated series since 1973. Although we got a few animated Short Treks one-offs in 2019, Lower Decks is the first time the Final Frontier has gone back to the cartoon zone since the '70s. And that begs the question:  Have you even seen the first animated Star Trek series?

Like any incarnation of Trek, Star Trek: The Animated Series has some episodes that limp around on impulse power and other episodes that hum along at warp speed. Not quite a kids’ show, and not exactly a hypothetical Season 4 of The Original Series, TAS can be a daunting show to jump into. Plus, if you just want to figure out what you missed, it might be hard to sort through some of the slower episodes. 

So, with that in mind, here are only the five most essential episodes of Star Trek: The Animated Series. If you’ve seen these five episodes, you’ve assimilated the best of what the first animated Trek has to offer. And, if you watch the episodes on this list, you’ll 100 percent be better equipped to catch even more Trekkie deep-cuts on Lower Decks.

No spoilers for Lower Decks ahead. Mild spoilers ahead for Star Trek: The Animated Series.

Credit: CBS

Who was the Captain of the Enterprise before Kirk? If you answered “Pike,” you’re not wrong, and if you answered “Archer,” you’re also not wrong, but that was a different Enterprise.

If you answered “April,” you are correct. Captain Robert April was the Captain of the NCC-1701 Enterprise before Pike, who was, of course, before Kirk. In this episode of The Animated Series, Captain April and his wife Sarah April visit the Enterprise just before their retirement. This episode established that April did at least one five-year mission aboard the Enterprise from 2245 to 2250, prior to Pike taking command. Basically, this means that, yes, in current canon, the Enterprise was running around in the galaxy for over 10 years before the start of Discovery, which means that, yes, the ship is 20 years old by the time Kirk takes command.

Though April was never mentioned in any other Trek beyond this episode, his existence was firmly made canon in the Discovery Season 1 episode “Choose Your Pain,” in which Saru called up a list of Starfleet’s most decorated captains. Later, in the Discovery Season 2 episode “Brother,” an Easter egg in Pike’s service record indicated he was April’s first officer. Meaning, Pike has been on the Enterprise a long, long time, too. So, want to see the first Captain of the NCC-1701 Enterprise get into it? Here’s your chance. 

Credit: CBS

Other than “Journey To Babel,” in The Original Series, “The Time Trap” probably features the widest variety of classic Trek aliens at the same time. When the Enterprise is stuck in a pocket universe, Kirk has to briefly team up with his old Klingon nemesis Kor. At the time this episode aired, there had never been an episode of Star Trek that featured this many different kinds of starships. Because the titular “Time Trap” is basically a Bermuda Triangle in space, the episode gives you a kind of outer space graveyard for space ships. If you’re into Trek for the sweet spaceships, this is patient zero 

But, beyond that, “The Time Trap” is notable because it’s the only other canonical appearance of Kor until his reappearance in the DS9 episode “Blood Oath.” Back during the original run of Trek, there were plans to bring Kor back numerous times, but the actor John Colicos was never available. To be clear, he wasn’t available for this either and is voiced by James Doohan here, who you know better as Scotty.

Credit: CBS

The writer of this episode, Howard Weinstein, was 19 years old when he sold the script. In a sense, this makes “The Pirates of Orion” the quintessential episode of The Animated Series. It was a Star Trek series that had to adhere to the standards of Saturday morning cartoons, but also be hip enough to work with the rest of Star Trek. So, what better story do you use to kick off your second season than a script written by a 19-year-old? 

The episode isn’t exactly deep or anything, but it’s all about Kirk fighting some Orions in order to get a drug that Spock desperately needs to survive. The Orions, recall, are the green-skinned folks, and since there’s an Orion on Lower Decks (Ensign Tendi, played by Noël Wells), it feels like a good time to brush up on the only episode of Trek to feature the Orions rocking their own space helmets.

Credit: CBS

Unlike literally any other episode of Star Trek, “The Slaver Weapon” is actually a literary crossover into the larger canon of a different science fiction universe. Written by SF legend Larry Niven, “The Slaver Weapon” is actually an adaption of his short story “The Soft Weapon,” which you can read in his collection Neutron Star. For SF readers of the '70s, Niven was mega-famous, and his “Known Space” shared universe spans over a dozen books and several short stories. The concept of “the Slavers” — an ancient alien race that once ruled the galaxy — comes from these books and stories. Ditto for the cat-like baddies, the Kzinti, who make their one-and-only appearance in Trek canon in this episode.

Back in the '90s, the canonicity of The Animated Series was heavily debated, meaning it was tricky to know if the Kzinti “really” counted as canon. But, TAS is canon these days, and if the Robert April thing in Discovery didn’t make that clear to you, then how about this: Riker mentions having some “trouble with the Kzinti” in the Star Trek: Picard episode “Nepenthe.” Showrunner Michael Chabon wrote to author Larry Niven to specifically ask if referencing the Kzinti again in Picard was cool. Yes, it turns out, it was very cool.

Credit: CBS

If there’s only one episode you watch of Star Trek: The Animated Series, it has to be this one. Featuring the return of the Guardian of Forever time portal from “City on the Edge of Forever,” this episode is more famous for establishing several aspects of Spock’s childhood, all of which would directly influence Trek canon forever. Remember when those bullies picked on young Spock in the 2009 J.J. Abrams reboot? Yep, that scene happened here first. Curious why Spock’s house looks the way it does in Discovery Season 2? Again, that’s established here. Even Ethan Peck’s audition for Spock subtly referenced the alternate universe that is briefly created in this episode. 

Written by the legendary D.C. Fontana, “Yesteryear” is an essential Spock episode. Keep in mind, Fontana was the writer who gave Spock his complexity, depth, and family backstory. If “Yesteryear” had been an episode of the live-action original series, it may have been a fan favorite. It’s just as good as “Amok Time,” and maybe a little better than “Journey To Babel.” Watch it and weep.

Star Trek: The Animated Series is streaming exclusively on CBS All Access.