On Adventure Time,Finn is possibly the last real human in Ooo. He was found in a forest by a pair of talking dogs, who raised him until their deaths (when Finn's adopted brother, Jake, apparently had a Promotion to Parent).
Darwin from The Amazing World of Gumball used to just be the Watterson family's pet fish, but he developed intelligence, grew legs, became Gumball's best friend, and the family adopted him as one of their own. The parallel to real life interracial adoption is made especially obvious by how all four of Darwin's voice actors in English are black, but the ones for the rest of the family are white.
In Amphibia, Anne Boonchuy is a 13-year-old human who finds herself trapped in a world where humanoid amphibians are the dominant lifeform... sort of. Although initially mistaken for a large, hideous, and terrifying monster, she soon builds an inseparable bond with the native Plantar family and becomes fully regarded as one of them. In this case, it is technically interspecies fostering since she still has a human family she means to return to, but regardless, on at least one occasion, Hop Pop refers to her as his "adopted granddaughter".
In the Arthur episode "Big Brother Binky," the Barnes family, which consists of bulldogs, adopts a Chinese bear cub named Mei Lin.
This is the premise of the Show Within a ShowHorsin' Around (which BoJack starred in during The '90s), which is about three human children being raised by a horse. Its rival show Mister Peanutbutter's House also involved this, with a dog raising three human children.
Diane and her family are mostly human, except for Diane's adoptive brother Gary, who's a sheep.
Hollyhock was adopted and raised by eight gay men in a polyamorous marriage, and none of them are horses like her (specifically they're five humans, a bear, a lizard and a duck).
In "The Stopped Show", Princess Carolyn, after trying all season to adopt a kid so she could become the mother she'd always wanted to be, finally succeeds in adopting an adorable porcupine baby girl she eventually names Ruthie.
Buzz Lightyear of Star Command probably topped this concept beyond most other examples by having a human girl being adopted by two robots.
An episode of Camp Lazlo showed that Samson (a guinea pig) has jellyfish for parents.
CatDog continually brought up one particular issue over the course of the series: Where did CatDog actually come from? For as long as they can remember, they'd always lived on their own. The series ended with CatDog going on a long journey to find their parents. It was never revealed howCatDog came to be, but for a brief time after they were born, they had been raised by a frog for a father and a sasquatch for a mother. They were all separated in a storm.
The main character, Buddy, is a T. rex who was adopted by a Pteranodon family.
The episode "All Kinds of Families" introduces Sunny Sauropoiseidon, who was adopted by Microraptors.
DuckTales (2017) has Lena following her adoption into the Sabrewing family. Even putting aside the whole Living Shadow thing, she's a duck and they're all hummingbirds.
In Final Space, Gary is forced to take on a Parental Substitute role to Little Cato after Avocato is killed. Though Little Cato starts off abrasive towards Gary due to mourning his dead dad, he quickly warms up to him, especially after learning that Gary lost his own dad too and they are "members of the same club" as he puts it. After suffering a long string of bad incidents in season two, including losing Avocato again shortly after getting him back via time travel, Gary offers to officially adopt Little Cato to help show him he isn't alone. Little Cato responds by happily hugging Gary. Little Cato still refers to Gary as his dad even after they save Avocato again, happy to have both his dads together.
Harvey Beaks: Technobear's parents are turtles. In fact, Technobear wasn't even aware that he was adopted and once asked if his shell would ever grow in.
In The Jungle Bunch, Maurice is a penguin who was raised by a tiger and now thinks he is one. Maurice himself has adopted a fish who now believes he also is a tiger.
Kipo and the Age of Wonderbeasts: Wolf was adopted by a family of Newton Wolves and the trope ends up being a horrific subversion as it turns out that they never intended her to be anything but training for their wolf children to hunt and kill. The wolf cloak she wears was made from the mother wolf. This brutal experience is why she's so cynical and doesn't believe that humans and mutes can live together peacefully.
Kitty Is Not a Cat: The title character is a human girl who was adopted by a group of cats.
Lambert the Sheepish Lion is a short where the Delivery Stork accidentally gives a sheep a lion cub for a child. When the stork tries to take him back the sheep refuses and she ends up raising the lion as her own. They're a happy family but Lambert is bullied by the lambs for being seen as a weird looking sheep, until as an adult he saves his mother from a wolf and becomes seen as a hero.
In Polish animated series Między Nami Bocianami (Between Us Storks) main characters are a family of storks that adopted a cuckoo. In a sense all cuckoos are adopted (although not by storks) so it's not so weird.
We learn from a flashback that Miss. Spider was separated from her mother when she was just a child and she got adopted by Betty Beetle.
In the pilot film, Miss. Spider adopted three children, each from a different bug species; Dragon (a dragonfly), Shimmer (a jewel beetle), and Bounce (a bedbug).
The two episodes "Little Ladybug Lost" and "A Beetle-ful Family" center around a young Asian ladybug named Grace who was separated from her family due to her oversleeping during her winter nap, and she winds up being adopted by Stinky the stinkbug and his sister Whiffy.
In My Little Pony: Friendship Is Magic, Twilight Sparkle (a unicorn) had to induce a dragon egg to hatch as part of her entrance exam in magic school. She ends up being a Cool Big Sis/Parental Substitute to the dragon, who serves as her underling and assistant. While Word of God previously said that it was actually Princess Celestia who raised Spike after he hatched, the episode "Sparkle's Seven" shows that Spike was raised by Twilight's family. Both fit the trope.
The New Adventures of Winnie the Pooh: The episode "Find Her, Keep Her" has Rabbit adopting a baby bird named Kessie after saving her during a storm. He grows attached to Kessie and has a hard time letting her go once it's time for her to fly south for the winter.
The title character of Oswaldo is a penguin who was raised by human parents.
Despite not seeming like the maternal type, and outright hating the idea at first, Eda Clawthorne, a witch, is the adoptive mother of King (a baby... dog-demon-thing. Later he's revealed to be a Titan, which throws even Eda for a loop). King even legally changes his name to share Eda's surname, and Eda's older sister and parents refer to him as their nephew/grandson. Eda is also the foster mother of Token Human Luz Noceda. Luz loves and misses her biological human mother Camila, but quickly accepts Eda as a second mother, and might as well be Eda's own child as far as they or the denizens of the Demon Realm are concerned.
In the second season, Luz's mother Camila is revealed to be living with Vee, a shapeshifting basilisk who has been impersonating Luz for months. When she finds out the truth, Camila is freaked out, but also quickly realizes that Vee is only a child who was in a truly terrifying situation; she at first impersonated Luz just to escape her oppressive and abusive upbringing, and then stuck around because of how kind and affectionate Camila was. Camila never even considers turning Vee away after learning the truth, and instead accepts that she now has two daughters.
In the third season, Camila's roster of adoptive non-human children expands, when Willow, Gus, Amity, and Hunter (three witches and a grimwalker, respectively) are all forced to flee the Demon Realm alongside Luz, and become refugees in the human world. Camila effectively becomes their foster mother, putting them up in her house and seeing to things like their nutritional and safety needs. She rolls with it remarkably well, though she admits she never expected to have six children.
Robin Robin is about a robin who was raised by mice.
Rocko's Modern Life: Heffer (a steer) is part of the Wolfe family. They originally took him for food but grew to love him and raised him as their own. The "birthmark" on his rump is where the wolves were going to divide him up. Amusingly, he evidently had no idea he wasn't a biological Wolfe until Rocko off-handedly mentioned it.
The Wildman from Samurai Jack was adopted by Tribe, a tribe of apes with white fur. Originally he was part of a tribe of humans enslaved by Aku, but was accidently left behind as a young child when he got loose from the Wheel of Pain machine the other humans were forced to operate and was taken in and raised by the apes. He doesnt remember his original family, but knows he's a human, and not an ape. Tribe has also trained him in the ability to "Jump Good" as they do, giving him the superhuman ability to jump miles in one stretch.
SpongeBob SquarePants: SpongeBob and Patrick adopted a baby scallop in one episode. It left other citizens quite confused when they thought about the biology involved.
In "Platyroo", Todd and his friends try to help a lost platypus named Pedro find his mother. They all think that Pedro's mother is a platypus like him, but at the end, they find out that she's actually a kangaroo. We also learn that Pedro has a pig for a little brother. In the same episode, Todd sees a frog in a family of ducks.
There's also a cat named Mitzi that adopts a group of puppies.
At the start of the series, we see how Yugo, an Eliatrope, was adopted as a baby by Alibert, an Enutrof. In later seasons, we see that he has also adopted Yugo's Dragon brother Adamai, as well as another couple of Eliatrope-Dragon siblings: Grugal and Chibi.
The cheapest ship Ruel could find in the second season is crewed by Black Ink and Elaine, a talking squid and his adopted human daughter.
Neither of Elyon's parents in W.I.T.C.H. are human, however they pass themselves as human. She didn't know that she was adopted until the Big Bad revealed her parents' true forms.
Work It Out Wombats!: Louisa is a tarsier, and her adoptive parents are kangaroos.
In the 2022 Short FilmThe Great Wolf Pack: A Call To Adventure by Great Wolf Entertainment note Division of American indoor water park and resort chain Great Wolf Lodge , Oliver the raccoon has parents who are red pandas.
