History Main / AbsentAnimalCompanion

** The early episode "[[Recap/MyLittlePonyFriendshipIsMagicS1E22ABirdInTheHoof A Bird in the Hoof]]" introduces Philomena, Princess Celestia's pet [[ThePhoenix phoenix]]. Philomena plays a major role in the episode, which establishes her as Princess Celestia's longtime and immortal pet, but she is never seen nor mentioned again for the rest of the series, with no explanation given for her absence.
** In "Dragon Quest", Spike ends up with a Phoenix egg, and it hatches into a baby Phoenix at the end of the episode, whom Spike names Peewee. We didn't see him again until "Just for Sidekicks", where we see through pictures that Spike tried to raise him, but ended up taking him back to his original parents.

* ''Series/SesameStreet'': In one segment, Ernie brings home a puppy for himself and Bert. The sketch ends with them coming up with names for the dog...maybe that's why they didn't keep it.

* ''WesternAnimation/GreenEggsAndHam'': In the first episode of season 2, one of the bills Guy is stressing over is "bamboo for the pandog." Said pandog never appears in the season. While it could conceivably be off-screen at home with Michellee while the other characters are off on their adventures, she winds up joining them at the end with the intention of permanently moving to Zookia, and no mention is made of having a pet.

* "WesternAnimation/TotalDrama":

* ''WesternAnimation/SheZow'': In the episode "Maz Junior", [=SheZow=] and Maz rescue a rare lizard from a greedy millionaire, Maz adopts it and names it Maz Junior. Who is never seen again.

* Pewku the giant crab vanishes before the climax of ''WesternAnimation/{{Bionicle}}: Mask of Light'' mostly because the plot didn't require her to be there (she was used mostly as transportation) and the film's ending went through substantial rewrites which even excluded her from crowd scenes. WordOfGod claimed she was given to new owners afterward.

* The opening battle of ''Film/{{Gladiator}}'' features Maximus' pet wolfhound, who had a prominent role on the battlefield up to helping its master by biting an enemy soldier's arm. But after the battle is over, the wolfhound just disappears.

* In the Creator/TomClancy novel ''Literature/PatriotGames'', Jack got his daughter a Labrador named Ernie. It does not appear in any later book, though a comment in ''Red Rabbit'', the next book in chronological (If not publication) order, implied that the dog stayed in America when the Ryan family moved to London for a year or so. No explanation is given for why they aren't reunited with the dog when they moved back to Annapolis.

** As for Tiger himself, he stuck around for a couple of seasons before vanishing without explanation. Even stranger, the final episode he appeared in was ADayInTheLimelight where the plot involves the kids devastated that they have to get rid of their pet because Bobby is allergic to him, only for a happy ending when it turns out he was allergic to something else. The reason for this was that, the day the episode was supposed to start filming, the animal handler discovered to his horror that Tiger had somehow escaped his kennel, ran out onto the freeway, and [[ActorExistenceFailure met a gruesome end.]] He ended up [[ReplacementGoldfish finding a lookalike at a pet store]] but since the dog wasn't trained the truth came out when they tried to shoot the scene where the kids say goodbye and the dog wasn't cooperating. They managed to get enough footage out of the dog to finish the episode but that was the last we saw of Tiger, ironically in an episode where he ''doesn't'' leave the Brady family.

* In the ''WesternAnimation/SonicBoom'' episode, "[[Recap/SonicBoomS1E4Buster Buster]]", after Sticks shakes a kitten out of a tree, Amy decides to get Sticks a pet to teach her the responsibilities of animal care. When Sonic takes Sticks to the pet store, Sticks finds every pet there [[TastesLikeDiabetes too cute, fuzzy, and adorable for her tastes]]. She then finds a disgusting robot dog that spits slime in a trash can and names him "Buster". Buster quickly annoys Sticks' friends, and it is later revealed that Buster was created by Dr. Eggman. When Buster transforms into a monster and attacks Sticks' friends, Sticks disciplines him to get him back to his normal self. At the end of the episode, Sticks lets Buster go, having found out he's an evil robot unfit to keep as a pet. Buster has not been seen or referenced since.

* ''WesternAnimation/ThePowerpuffGirls'': In the episode "Pet Feud", Professor Utonium creates the perfect pet named Beebo. Beebo is the main focus of the episode, and at the end of the story all inhabitants of Townsville get one, but they are never seen or even mentioned again afterwards.

** In "Dragon Quest", Spike ends up with a Phoenix egg, and it hatches into a baby Phoenix at the end of the episode, who Spike names Peewee. We didn't see him again until "Just for Sidekicks", where we see through pictures that Spike tried to raise him, but ended up taking him back to his original parents.

* In the ''Literature/HarryPotter'' books, some of the main cast's pets--namely, Hermione's cat Crookshanks, Neville's toad Trevor, and Ron's owl Pigwidgeon-- aren't mentioned in the final book, leaving their status ambiguous at the end of the series.

* Tweety, the pet canary in ''Film/{{Poltergeist}}'' dies, and Carole-Anne asks for a replacement goldfish. Soon after, she's feeding goldfishes Tweety II and Tweety III. They remain for one scene with no sign they afterwards ended up in the closet with the rest of the bedroom's contents.

* The opening battle of ''Film/{{Gladiator}}'' features Maximus' pet wolfhound, who had a prominent role on the battlefield up to helping its master by biting an enemy soldier's arm. But after the battle is over, the wolfhound just dissappears.

Asides the aforementioned syndication issue, there are other reasons why this happens. It may be an issue of [[LawOfConservationOfDetail conserving detail]], and the pet simply isn't shown again because it isn't necessary for the current story. There's also the matter that whenever an animal appears on a TV show, trainers and/or representatives of animal-welfare organizations have to be present, which costs money and resources the production company may not want to spend long-term. There's also the fact that working with various animals has its own unique challenges, such as the fact that some animals simply don't live very long and others [[NeverWorkWithChildrenOrAnimals might not behave]]. So it's not altogether surprising that many studios don't want to deal with animals more than is necessary.

* Pewku the giant crab vanishes before the climax of ''WesternAnimation/{{Bionicle}}: Mask of Light'' mostly because the plot didn't require her to be there (she was used mostly as transportation) and the film's ending went through substantial rewrites which even excluded her from crowd scenes. WordOfGod claimed she was given to new owners afterward.

* One scene in ''Film/ItsPat'' shows that Pat has a cat, Muffy, who is never seen or mentioned again after the one scene. This scene is done to [[RunningGag once again]] [[AmbiguousGender trick the audience into thinking that the mystery of Pat's gender is revealed]], as Chris says to Pat, "I love to stroke your pussycat", before we see the cat.

* ''Literature/DiaryOfAWimpyKidDogDays'':
** Rodrick and Greg get a fish each. Greg's fish dies, but Rodrick's fish survives, yet still is never seen again.

* Jaller in the ''Literature/{{Bionicle}}'' books of the underwater Mahir Nui arc uses a Hahnah crab that saved his life to carry his [[GatlingGood gatling gun]]. The animal was even included with Jaller's toy. When he and his team get teleported back to dry land by Matoro, the Hahnah is absent and not brought up again. The writer explained that Matoro just wanted to save his friends and didn't care for the animal, which so remained in the sea. At least Jaller got to keep his gun.

* ''Series/HappyDays'': In "Two Angry Men", Fonzie has several pigeons as pets, but we never see them in future episodes.

** In ''Dragon Quest'', Spike ends up with a Phoenix egg, and it hatches into a baby Phoenix at the end of the episode, who Spike names Peewee. We didn't see him again until ''Just for Sidekicks'', where we see through pictures that Spike tried to raise him, but ended up taking him back to his original parents.

* Amy Farrah Fowler has a smoking pet [[EverythingIsBetterWithMonkeys monkey]] in one episode of ''Series/TheBigBangTheory'' that is never mentioned again after that episode. Fowler is actually forced by her academic superiors to relinquish the monkeys she keeps at home. Not because of the smoking or the unauthorised taking her work home with her, but for "unprofessional behaviour": when monkeys crazed by nicotine deprivation started flinging excrement at her in protest, she ''threw it right back''.

* During the Sinnoh arc of the ''Anime/{{Pokemon}}'' anime, Paul caught a Gliscor at the same time as Ash caught his Gligar. The implication was that Gliscor would become TheRival to Gligar, but Gliscor made only two further appearances (one of those being a cameo) before disappearing with no explanation.

* In the WesternAnimation/KingOfTheHill episode “Pretty, Pretty Dresses” Bill at one point buys an iguana he names Lenore after his ex-wife to try to help cope with his loneliness, it gets spooked by Ladybird, the Hill’s bloodhound and runs away, later on Hank finds it and returns it to Bill, the rest of the episode deals with Bill losing his mind and starts wearing his ex-wife’s clothes she left behind, believing himself to be her, the iguana is never seen again after that scene and for the rest of the series.

* ''WesternAnimation/SheZow'': In the episode "Maz Junior", SheZow and Maz rescue a rare lizard from a greedy millionaire, Maz adopts it and names it Maz Junior. Who is never seen again.

* In the WesternAnimation/KingOfTheHil episode “Pretty, Pretty Dresses” Bill at one point buys an iguana he names Lenore after his ex-wife to try to help cope with his loneliness, it gets spooked by Ladybird, the Hill’s bloodhound and runs away, later on Hank finds it and returns it to Bill, the rest of the episode deals with Bill losing his mind and starts wearing his ex-wife’s clothes she left behind, believing himself to be her, the iguana is never seen again after that scene and for the rest of the series.

** "Plankton's Pet" involves Plankton getting a pet amoeba, Spot, to train to be a guard dog and to steal the Krabby Patty formula. Spot isn't seen again until two seasons later, in the aptly named "Spot Returns" - which is less about him and more about Plankton training his pups to steal the formula. From then on, the trope is {{Subverted}} as Spot has made a few on-and-off appearances since then (in "Bottle Burglars", "Gary & Spot", and "A Place for Pets") and is still Plankton's pet.
** In "A Pal for Gary", [=SpongeBob=] gets a new pet named Puffy Fluffy. Later on in the episode, however, [[spoiler:Puffy turns into a monster and goes on a Godzilla-esque rampage.]] He eventually runs away.