Star Trek's Pets, Ranked From Worst To Best

Odds are that when you think of Star Trek, your first thought isn't, "I love their pets." But the truth is that Trek has a long history of giving its characters loyal animal companions. You can find memorable pets in every single Trek series and even some of the movies, ranging from creatures that are cuddly to beings that are traumatically gross.

In fact, pets both mundane and of the alien variety have come closer to center stage with more recent Trek series, such as Discovery, Picard, and Lower Decks. But here's the honest truth — Trek pets aren't created equal. While these critters are all going where no pet has gone before, they're not all worthy of the Star Trek mantle. On the flip side, some of these lovable animal friends have made the franchise that much cuter (or, in some cases, creepier). From floofy love bugs to disembodied AI, here are the pets of Star Trek, ranked from worst to best.

In the Star Trek: The Next Generation (TNG) episode "Realm of Fear," Enterprise crew member Reggie Barclay (Dwight Schultz) is terrified of using the transporters. Sympathetic to Barclay's struggles, Chief Miles O'Brien (Colm Meaney) tries to make him feel better by relating his own battle with arachnophobia. 

At the time, O'Brien's anecdote doesn't seem to have much impact on Barclay, and Reggie eventually conquers his fear of the transporter. The story ends with Barclay and O'Brien meeting in Ten Forward for drinks where the latter unveils his pet tarantula, Christina. During their earlier conversation, Barclay says he's never had a problem with spiders, but once O'Brien steps away and Christina starts crawling on Barclay's arm, he seems to have changed his mind about arachnids. 

Christina is so low on our list because, in spite of O'Brien still having a couple of TNG appearances after "Realm of Fear" — not to mention his seven seasons as a regular cast member on Star Trek: Deep Space Nine (DS9) – we never see or hear from Christina again.

When Reggie Barclay invites his old therapist, Deanna Troi (Marina Sirtis), over for a visit in the Star Trek: Voyager episode "Pathfinder," he tells her he's worried that he's slipping into obsessive behavior. One little piece of proof not only stops by to visit, but it eats some of Troi's ice cream. 

After the events of 1996's Star Trek: First Contact, Barclay is transferred to Project: Pathfinder, which is tasked with the goal of finding a way to communicate with the distant Voyager. To that end, Barlcay regularly spends long hours with holographic recreations of Voyager's crew, with whom Barclay is growing obsessed. In fact, he names his fluffy white cat Neelix after the Talaxian Voyager crew member (Ethan Phillips). 

While Neelix the cat is mentioned after "Pathfinder," we never see him again, which explains his low spot on our list. Strangely, while pets seem to take rather well to Barclay, they also tend to not show up after they meet him. Maybe it's something he said?

While there are other starship captains with pets, we don't know of any besides the ruthless Commander Kruge (Christopher Lloyd) of 1984's Star Trek III: The Search for Spock who keeps the beasts with them on the bridge. 

We never actually get a name for Kruge's monster dog — not even its species. Simply by virtue of the thing being the pet of a Klingon, it's possible this is one of the oft-mentioned targs. However, targs wouldn't be mentioned until TNG and would look different than Kruge's slimy beast, so for now, it belongs in the "who knows" file. 

We never see the fierce canine hurt anyone aboard Kruge's Bird of Prey, but he certainly looks like he could. When Kruge orders his men to feed the beast, the brave Klingon warriors seem visibly uncomfortable about the prospect. 

Sadly, Kruge's time with his pet is cut short. Whatever species it is, the beast is electrocuted during the brief exchange of fire between the Klingon ship and the Enterprise.

Perhaps the most unique Trek pet we know of is introduced in DS9's first season. In "The Forsaken," an unmanned probe emerges from the Bajoran Wormhole. After the station interfaces with the probe, Chief Miles O'Brien notices DS9's computers are working better than ever, but that doesn't last long. O'Brien tells Commander Sisko (Avery Brooks) that the computer is acting like a young "pup." Every time O'Brien leaves Ops, the chief explains, something goes wrong that brings him back, as if the computer were a puppy desperate for attention. 

It's determined that Pup is a sentient program. To resolve the issue, O'Brien writes what he calls a "doghouse" program meant to occupy Pup so it won't keep wreaking havoc. Presumably, Pup stays in the station's computers for most, if not all, of the rest of the series, if it was lucky enough to survive certain incidents. For example, in the season 5 finale "Call to Arms," Kira Nerys (Nana Visitor) sets off a program designed to incapacitate DS9's computers when the Dominion takes over the station. Pup isn't mentioned again in the series, so it isn't clear if it survived.   

Probably no other pet in Star Trek's history is mentioned as often while, at the same time, as rarely seen as the unnamed Pyrithian bat that Dr. Phlox (John Billingsley) keeps in the sickbay in Star Trek: Enterprise. One of the only times we see her is in season 2's "A Night in Sickbay," when Captain Archer (Scott Bakula) is watching over his own ailing pet — the beagle Porthos. Archer wakes up to what sounds like Phlox cursing in his native Denobulan because the bat has escaped her cage. In a funny scene, Archer and Phlox repeatedly fail to recapture the bat, only to have Ensign Sato (Linda Park) wander in and pluck it out of the air with ease.

Enterprise fans might wonder why we don't mention the rest of Phlox's impressive menagerie of sickbay critters on this list. The truth is, we don't think you can call most of Phlox's animals "pets." He uses most for research or for treatment, and it isn't uncommon for them to be sacrificed in the process. The Pyrithian bat is an exception. 

Ever take care of a pet out of guilt? Well, meet Chester the cat. When Starfleet Intelligence taps Miles O'Brien to go undercover in the Orion Syndicate in the DS9 episode "Honor Among Thieves," the engineer wins the trust of old-timer Liam Bilby (Nick Tate). The first time Miles visits Bilby's home, the old crook warns him that there's a chair only Chester is allowed to sit in. And one of Bilby's final requests before the Syndicate murders him is that Miles take care of Chester. Miles honors the request and brings Chester back with him to DS9, much to the chagrin of his wife, Keiko (Rosalind Chao).

Chester isn't seen much after that, though he does show up a bit later in season 6's "Time's Orphan." Now that we think of it, maybe Chester answers the mystery O'Brien's missing pet spider, Christina. Perhaps Chester decided the O'Brien's DS9 quarters were only big enough for one pet, and the cat had a full lunch that day.

If you've seen even a couple episodes of TNG, odds are you've caught a glimpse of Livingston, Captain Picard's pet lionfish that he keeps in his ready room's aquarium. Starting with its premiere episode, Livingston appears regularly on TNG. For example, the Borg Hugh (Jonathan Del Arco) takes great interest in Livingston in "I Borg," and a caveman Will Riker (Jonathan Frakes) tries to eat him in "Genesis."

In a 2011 interview with StarTrek.com, Ronny Cox told an ironic anecdote about Livingston. Cox played one of the most hated Starfleet captains — Captain Jellico — in the two-parter "Chain of Command." Here, Jellico takes over the Enterprise for most of the story, and one of the things that irked fans is that he orders Livingston removed from the ready room. 

But according to Cox, this was something of "a bone" the production crew threw to Patrick Stewart. Cox said Stewart "was always after them to take the fish out of the ready room" because he felt having a "captured species" in the Enterprise went against the ethos of Star Trek.

When it came time for the 1973 episode "Yesteryear" — the second episode of Star Trek: The Animated Series — the writers didn't forget their history. In The Original Series episode "Journey to Babel," Spock's mother, Amanda (Jane Wyatt), says that her son had a pet sehlat as a child, which she describes as "sort of a fat teddy bear." 

We get to meet this "fat teddy bear," I-Chaya, in "Yesteryear" when the beast proves much more heroic than Amanda's description of him would leave you to believe. Spock (Leonard Nimoy) travels back in time to save his younger self, who goes to see if he can pass the traditional kahs-wan survival test earlier than he should. During the test, a predatory cat called a le-matya attacks the child Spock, and I-Chaya rushes in to protect the boy. The adult Spock intervenes, and I-Chaya seems fine at first, but it soon collapses, suffering from the poison in the le-matya's claws. 

While they find a healer, the poison is too far along, and young Spock is forced to make the heartbreaking decision of euthanizing him.

Even if we tried — and many have — we couldn't forget the tribbles. These cute, cooing little balls of fluff prove to be full blown menaces starting in the famous Original Series episode "The Trouble with Tribbles." Being already pregnant upon birth, a tribble who's fed any food will soon give birth to another, and soon, they'll be breeding faster than a horde of gremlins at the bottom of a lake. While they've sometimes been a mixed blessing, like when they help identify a Klingon secret agent in "The Trouble with Tribbles," there are also examples of them being nothing but harbingers of calamity, like when they lead to the destruction of the USS Cabot in Short Trek's "The Trouble with Edward." 

Because of their nature, you wouldn't think most people would be able to keep tribbles as pets for very long. One noteworthy exception is Discovery's Captain Lorca (Jason Isaacs), who keeps a pet tribble in his ready room. Considering the nature of Lorca's Mirror Universe origin, it could be that his more brutal upbringing rendered him more able to resist the urge to feed the potentially troublesome puffball.

In July 2019, during the promotional lead-up to Star Trek: Picard's release, the first official poster for the series was released, and Jean-Luc Picard wasn't the only one on it. At his feet was a gorgeous pit bull whose name we soon learned is, hilariously, Number One. 

When speaking to StarTrek.com in January 2020, Patrick Stewart said the decision to include Number One — whose real name is Dinero — was creative and also a little political. Stewart said that he felt Number One's presence would "say a lot about [Picard], that he now has a dog always at his side." He also said he's part of a campaign trying to overturn legislation that bans pit bulls — which he calls "the most sensitive, the most loving, the most giving, the most affectionate creatures that you could ever possibly hope to meet" — from the UK. 

Sadly, Number One doesn't show up much in Picard after the beginning. However, considering Stewart's feelings about Livingston the fish, it makes sense Picard wouldn't want to confine a dog to a starship when the pooch could be happily exploring Picard's ancestral vineyard grounds.

Our nightmares won't let us forget the pet that Khan (Ricardo Montalban) uses to help in his quest for vengeance against James Kirk (William Shatner) in 1982's Star Trek II: The Wrath of Khan. 

As Khan describes to the captive Chekov (Walter Koenig) and Captain Terrell (Paul Winfield), young Ceti eels slither into a victim's ears and wrap around the cerebral cortex. This renders the victims vulnerable to suggestion, drives them insane, and ultimately kills them. Khan then drops two young eels in Chekov and Terrell's helmets. We get to watch as the baby Ceti eels creep along their cheeks and burrow into their heads. That this remains one of the most disturbing scenes in any Trek media is a big part of why the beast makes it so high on our list.

Thankfully, it seems likely that Ceti eels won't be showing up in any pet stores in future Trek shows or movies. Khan's eel is the last of its kind, and whether he brought it aboard the Reliant or left it behind, it won't be messing with anyone's ears anytime soon.

Some Trek characters find their pets, some grudgingly accept them, while at least one of them just builds her own. In the Star Trek: Lower Decks episode "Much Ado About Boimler," Ensign D'Vana Tendi (Noël Wells) builds a dog named simply "the Dog." The thing is that as an Orion, Tendi has never actually had a dog, so the genetically engineered creature she brings to life includes a number of abilities that she apparently thinks are normal for canines.

Among other things, we witness the Dog spit lightning-like electric bolts, sprout wings from its eyes, walk on walls, and shape-shift into pretty much anything it wants to. We're not sure exactly where Ensign Tendi gets the idea that these things are normal for pet pooches, but we're pretty sure it wasn't from a Clifford book or a Lassie flick.  

Ironically, when Tendi comes across a real dog later in the episode and it licks her face, the experience grosses her out. Flying bat-winged eyeballs? Fine. But when a dog gets affectionate, she can't handle it.

There are fierce pets, cute pets, and horrifically disturbing ones. But how many pets — even on Star Trek — can answer ship-to-ship signals on the viewscreen? Not many, but that's exactly what Grudge the cat does (well, kind of) in the Discovery episode "Scavengers." Grudge travels with the 32nd-century courier Cleveland Booker (David Ajala), aka Book, and when Book's ship returns to Discovery, the crew isn't met by Booker's face but by the fuzzy visage of Grudge.

While Grudge is a beautiful creature, it's fair to say we're not so much in love with the kitty as we are with the wide variety of extreme emotions Grudge provokes. Georgiou (Michelle Yeoh) unleashes a torrent of jokes about Grudge's size whenever she's mentioned, Ryn (Noah Averbach-Katz) is terrified of her, and Ensign Tilly (Mary Wiseman) just doesn't know what to do with her. Meanwhile, Book reacts to any anti-Grudge slight with, "She's a queen," and, in at least one case in the season 3 finale, by booting the offender to his death.

Star Trek: Enterprise's Captain Jonathan Archer doesn't share Picard's desire to leave dogs at home. From the series' premiere to its final episode, Porthos the beagle stays with Archer aboard the eponymous vessel. While he isn't very helpful as far as fighting off the Suliban or fixing the ship, Porthos doesn't let anyone intimidate him. He'll happily stare down any invading enemies, as he does to the Ferengei marauders who hijack the ship in season 1's "Acquisition." 

Porthos is the center of one of the most emotionally harrowing episodes of Enterprise. In "A Night in Sickbay," the pooch is dying after being infected by an alien pathogen. Thankfully, Phlox is able to nurse him back to health. And while it never makes him quite so sick as in that episode, Captain Archer is often unable to resist giving the Beagle cheese, which causes Porthos, Archer, and Phlox some difficulties after digestion.

Porthos is one of the few Prime Universe pets to get a shout-out in the Kelvin timeline, by the way. In 2009's Star Trek, Simon Pegg's Montgomery Scott makes mention of Admiral Archer's "prized Beagle."

The number one spot needs to go to, well, Spot. Starting with TNG's season 4 episode "Data's Day," Spot is Data's (Brent Spiner) loyal companion for the rest of the series, as well as appearing in 1994's Star Trek: Generations and 2002's Star Trek: Nemesis. Spot gets along with Data better than she does any human, and the feeling is mutual — at least they are as soon as Data has feelings. 

While it isn't the most beloved Star Trek movie, Generations includes one of the franchise's most touching moments, thanks in part to Spot. Towards the end of the film, Data discovers Spot is alive amidst the wreckage of the Enterprise-D. Having a new chip that gives him human emotions, Data cries tears of joy. The sensation is so strange to him that he believes the chip is malfunctioning.

And if you're curious about what happens to Spot after Data's death in Nemesis, the film's special edition DVD includes a deleted scene that reveals Spot finding an unlikely caregiver. Worf (Michael Dorn) and Geordi (LeVar Burton) are tasked with cleaning out Data's quarters. As they do, Spot emerges, climbs onto Data's desk, and jumps into Worf's arms. The Klingon says, "I am not a cat person." Smiling, Geordi answers, "Looks like you are now."