In animation and comics, animal characters develop and age like humans. In reality, they tend to have much different lifespans, ranging from mere weeks to centuries longer than any human could hope to live. In addition, they usually develop quite differently and sometimes have life stages that are completely alien to humans. For example, frogs and toads have tadpole, froglet, and adult stages, butterflies and moths have larval (caterpillar), pupal, and adult stages. Crickets and grasshoppers have nymph and adult life stages, which are less drastic.
This trope takes on four different forms, human-like lifespan and longevity, human-like aging process, human-like developmental process, and human-like baby animal body proportions.
- Human-like Lifespan/Longevity: This is when an animal character has the same longevity as a human, that is, live as long as a human. Depending on the species this is either accomplished by shortening or lengthening their life span, though the lengthening of the short-lifespanned animals form is far more common. A way to avert this is to use the species' normal life span, and give a multiplier to calculate how old the animal would be if it was a human. For example, a normal year would be seven "dog-years": a two-year-old dog is about as old as a fourteen-year-old human.
- Human-like Aging Process: This is when an animal character shows their age in the way that a human does. Examples of this include gray hair or fur even on a non-mammal character, wrinkles, liver spots, bushy eyebrows, mustaches, and/or beards, balding head (often in the form of Furry Baldness), and sagging Non-Mammal Mammaries.
- Human-like Development Process: This is when an animal character develops in the way or at the pace that a human does.
- Human-like Baby Animal Body Proportions: This is when baby animal is inaccurately given body proportions like those of human babies. For example, real-life calves, fawns, lambs, and foals have long legs, so that they can stand shortly after birth and reach to suckle. Some examples are animal equivalents of the Three-Month-Old Newborn trope.
- Precocial Altricial Baby Animals: This is when a baby animal of an altricial species is inaccurately portrayed as less altricial or more precocial than in real life. One variant is an animal that is born furless or hatches featherless in real life is depicted as being born fully furred or being fully feathered when it hatches. Newly-hatched songbirds, parrots, and pelicans are featherless and helpless in real life, but tend to be portrayed as fluffy, yellow, and precocial as ducklings and chicken chicks in fiction. Some examples are animal equivalents of the Three-Month-Old Newborn.
Averting or lampshading this trope is sometimes done as a Furry Reminder.
Human-like Lifespan/Longevity Subversions, Lampshades, and Exceptions:
- Akamaru from Naruto is two years old at the start but is still only a small puppy. Within not even three years, he hit a huge growth spurt. As a puppy he rode on Kiba's head, but as an adult Kiba could ride him like a horse. In the final chapter he's very, very old looking but alive over ten years later. Large dog breeds tend to have short lifespans. At six Akamaru is a sprightly adult but for even small dogs that's nearing the end of middle aged. In Akamaru's case it can be justified in that he's a fictional breed of ninja dog.
- The My Little Pony: Friendship Is Magic fanfic A Mighty Demon Slayer Grooms Some Ponies zig-zags this. In the ancient era, Ponyland's ponies age like horses (a pony remarks that an eleven-year-old human is "two in pony years"). Over the next several thousand years (by the Friendship is Magic era) they become much more humanlike, including having a human lifespan and aging at a human pace.
- Inverted in Claro de Luna, Octavia (a pony) died of old age at twenty-six. This accentuates the MayflyDecember Romance between her and the millenia old Luna. In canon, ponies are shown to age comparably to humans.
- Implied in Letting Go Of Hate. Kiara, an almost-fully-grown lion, mentions having been a "preteen" once.
- In the first Madagascar when Marty the zebra turns 10, it's hinted that he is middle aged at that age. Zebras can live to be 40 years old in captivity.
- It's justified in the case of The Secret of NIMH, where the rats and mice who were experimented on at NIMH were given long lifespans. It's mentioned that Johnathan Brisby would have far outlived his wife, a simple field mouse, had he not been killed by a cat first.
- In Fantastic Mr. Fox, the characters' ages are often given in fox years. Apparently six fox years is about as long as a normal year; Ash is two years old in non-fox years, but about twelve in fox years (and is about as developed physically and mentally as a twelve-year-old human child). Mr. Fox gives his age as seven non-fox years, which makes him about as old as a forty-two year old human.
- In Willy the Sparrow, Willy (a human transformed into a sparrow) and Cipur are exactly the same age. Willy is in his early teens, Cipur is a very old bird.
- Mentioned but not elaborated upon in The Beginning, the last book of the Animorphs series. Tobias, a human trapped in morph as a red-tailed hawk, briefly mentions that he's old for a red-tail, but he has absolutely no idea how much time he has left.
- Justified in Harry Potter and the Prisoner of Azkaban in regards to Scabbers, Ron's pet rat that had been alive for at least 12 years and had belonged to Ron's older brother before him. Ron is told by a magical pet shop owner that a plain country rat such as Scabbers generally doesn't live more than a few years, but of course it's revealed that Scabbers is really Peter Pettigrew, a traitor and presumed dead wizard in disguise.
- The woodland creatures of Redwall track time's progression by seasons, not years, presumably because of their respective species' shorter-than-human lifespans.
- Originally averted by Garfield, who mentions on his second birthday that the human equivalent of fourteen, and complains about aging ever since he turned four. Later played straight, as he's still relatively healthy and active over 30, though the average lifespan of a housecat is 12-14 years at the least and 20 years at the most. It's possible for cats to live longer than 20 however. In Scotland, there was a cat that was reported to have lived to be 43 years old. While there are unconfirmed reports of cats living longer, like the aforementioned report, the oldest cat ever recorded, Creme Puff, was 38 years and died three days later.
- Bug Fables justifies this trope as part of the Anthropomorphic Transformation brought upon by the "Great Awakening". Notably, the lifespans seem to be increased proportionally; termites still live longer than ants, and the queens are implied to live for even longer than that, with the Ant Kingdom innkeepers having gone through several generations in the time it took for a single change of Ant Queen.
- Sonic the Hedgehog:
- Sonic and his friends. Most of them, including Sonic himself, are stated to be teenagers between 14-16, while the younger ones such as Tails are between 6-8. Amy Rose is in the middle at 12. Their ages are a case of All There in the Manual, but they typically do behave the same as humans that age.
- Sonic's origin as given in the American Sonic the Hedgehog Bible averts this. Sonic doesn't age like an actual hedgehog, but he doesn't age like a human either. It took only a year for him to turn into the equivalent of a teenager.
- Arizona from Them's Fightin' Herds is a one year old Partially Civilized Animal calf. Other characters age similar to their real counterparts. Unicorns and longma age slower than "normal" animals.
- The birds of Hatoful Boyfriend are all uplifted, large and sentient. They grow up somewhat more slowly than normal birds, but faster than humans. Yuuya mentions that doves hit sexual maturity before they're a year old. They also live longer than normal birds but still have shorter lives than humans, though it's never said just how long. Normal pigeons in good conditions can often reach fifteen years of age, but there are reports of individuals reaching forty.
- Inverted in Nekopara as a case of Animallike Human Aging, all catgirls grow and age like their real life counterpart, the most absurd example goes to Coconut, being a Maine Coon, she has the body of an adult woman despite being 1 year old.
- In the Phineas and Ferb episode "Phineas and Ferb's Quantum Boogaloo" Candace travels 20 years into the future where Perry is still alive, though old. In reality, platypodes only live for 10 years.
- The lifespan part of this trope is averted with Brian Griffin the dog from Family Guy as occasional references are made to his age (seven) and longevity. Also, Peter also addressed the fact that Brian will only live a fraction of the time Peter will.
- One episode of Pinky and the Brain hinted at the lifespan of real mice, which is 2-4 years. Brain says that at 2 years old, he's lived half his life.
- This isn't mentioned, but it's strongly implied in Chip 'n Dale Rescue Rangers. In the pilot, when Gadget is added to the group, it's mostly because she is the daughter of a friend of one of the protagonists, and she is the only one who can fly his plane now that he is dead. It is mentioned that said friend and protagonist fought together in "The Great War", which seems to be an expy war for World War II. For any of this part of the pilot to work, either:
- a) Gadget was born about a decade or so after the real actual WWII, making her actually anywhere from 20-30 something at the time of the pilot
- b) The Great War isn't an expy for WWII, but a more recent conflict such as Vietnam, and Gadget is actually 12, and demonstrating a "puberty = adulthood" trope
- c) Gadget and every other animal is aging just like they should, The Great War happened in the past 3 or 4 years, is not an expy for any human war, and is an expy for a covert black ops action instead
- d) It's not the late 80's in the show
- As all the visual evidence, parody, and inferences point to a) (right down to the plane they fly), and in the show, it's clearly the late 80's, this trope has to be in play.
- Also of note is that Monterey Jack references surviving things that supposedly happened decades ago in his long rants about the past (braving the "Great Blizzard of '38" for example). How truthful they are varies, however.
- Pound Puppies (2010) lampshades this trope in one episode.
- Surprisingly averted in Dora the Explorer. A Christmas episode shows that Swiper, Boots, and several of the animals are the exact same age. Boots is a child, Swiper is an adult, and the others are varying degrees of vague. When they go into the future less than six years Swiper, who is a fox, is a senior while Boots the Monkey isn't even a teenager yet.
- Scooby-Doo: Scooby is a seven year old Great Dane. Danes have a typical lifespan of under ten, and even to a smaller breed seven would be old, but Scooby isn't presented as anything but a young adult.
- In All Hail King Julien, the Grumpy Old Man lemur is implied to be in his 20s, which would be an appropriate age for an old lemur, who have been known to live to their 30s. Meanwhile, Mort implies that he could be as old as 50, which is remarked upon by Julien to be an excessively high age for a lemur.
- One episode of Puppy Dog Pals Bingo and Rolly celebrate their first birthday, they should be fully grown but they still have child voices and are still referred to as puppies.
Human-like Aging Process Examples:
- Nagasarete Airantou: The animals of the island, besides looking strange to outsiders, age at the same pace as humans. And also has the same average life span as well.
- In One Piece, the Fishmen (a Fish People, not a Half-Human Hybrid) age not unlike humans. Evidenced in Hody Jones and his New Fishman Pirates, who, after a steroid-induced Rapid Aging, are shown with wrinkles, saggy eyesockets, gray beards and teeth loss.
- We could know that Master Shifu in Kung Fu Panda is old by his white mustache, bushy eyebrows and grayish fur (and not to mention being really small).
- Rufus the cat from The Rescuers has a grey moustache that indicates his old age.
- Jock the Scottish Terrier from Lady and the Tramp has a grey moustache and bushy grey eyebrows.
- While he certainly has a far longer than human lifespan, some of the clues to Star Wars' Yoda's advanced age include wisps of gray hair and the fact that he is almost always seen either walking with a cane or in a scifi version of a wheelchair.
- The animals in Leafie, a Hen into the Wild age realistically however an older duck is shown with markings resembling a grey beard and bushy eyebrows.
- Inverted with Warhammer 40,000's Space Wolves, who undergo Animal-like Superhuman Aging: As they grow older, Space Wolves gain wolf-like characteristics thanks to a mutation of their geneseed: their hair grows gray (from its original black, blond or red), their canine teeth grow more proeminent, and their eyes turn gold. Some even go too far, becoming animalistic Wulfen.
- In "The Old Gray Hare," after a Flash Forward to the year 2000, a 70-or-so-year-old Bugs Bunny is shown with white chin whiskers.
- The Tom and Jerry cartoon "The Missing Mouse" has Jerry Mouse pose as an escaped lab mouse filled with a volatile explosive. Jerry's ruse dissolves, however, and Jerry gets booted out of the house. Tom soon captures another mouse, thinking Jerry is repeating the trick. When Jerry shows himself elsewhere, though, Tom realizes that he's abusing the explosive mouse. This realization ages Tom dramatically: white eyebrows, white ear-hairs, baggy skin, collapsed posture. He looks like a centenarian.
- The grandmother in Max and Ruby is grey furred instead of white furred like her grandchildren.
Human-like Development Process Subversions, Lampshades, and Exceptions:
- Many coming of age Disney movies that feature Nearly Normal Animals, like Bambi, The Lion King, Lady and the Tramp, and The Fox and the Hound avert this by showing the animals develop and age like their real counterparts.
- In the Redwall series most animals seem to use "seasons" as a substitute for years, Tagg for example is stated to be an adult at 16 seasons. They seem to equate one season to one year, and that's still far too slow. In the example that's given of Tagg, to be realistic he would have had to have been an adult by around 13 months, or just over four seasons. Also, the mice ought to be fully grown in well under one season.
- While the movies avert this The Lion Guard does not. Kion and Kiara are not litter-mates yet are close in age. In real life lions have larger gaps between litters and Kiara should look older.
- In DuckTales (2017) ducks are actually born from eggs which has a surprising amount of plot relevance, because it means Della has never seen her sons alive in person. This drama obviously wouldn't be possible if they were born alive like humans are.
Examples of Human-like Baby Animal Body Proportions:
- Partially averted with the fawns in Bambi as they have long, ungainly legs like real fawns, but round heads and high foreheads like human babies.
- The calves and lambs in the Mickey and the Beanstalk of Fun and Fancy Free have long, ungainly legs like real calves and lambs. In fact, many other classic Disney works that show calves, lambs, and fawns show them with the correct leg proportions.
- Newborn lions in The Lion King are basically the animal equivalent of the Three-Month-Old Newborn trope. They're large and already have their eyes open.
- Calves (baby cows) with large heads and stubby legs. However, the foals (baby horses) have long legs, like real foals.
- Story of Seasons usually plays this straight, as the babies are typically stubby mini versions of their mother. Harvest Moon: A Wonderful Life averts it by having realistically proportioned animals.
Examples of Precocial Altricial Baby Animals:
- In Ratatouille, all the baby rats that are seen evacuating the colony's old home are fully furred and open-eyed, with not a pinkie to be seen.
- A Bug's Life: The baby songbirds at the end that devour Hopper are shown to be cute and fluffy, like baby chickens. In truth, the newly-hatched young of many songbirds are in fact blind, featherless and rather hideous-looking, at least for the first few weeks.
- Kittens, both ocelot and cat note , are born with their eyes open and with their genetically predetermined eye color (green for the black tuxedo and ginger tabby cats and blue for the seal point Siamese cats) already showing, making them literal Three-Month-Old Newborn kittens. Real cats/wildcats open their eyes at seven days and their adult eye color appears at as early as six weeks.
Examples of Two, Three, Four, or All Forms:
- The Wild: Ryan is stated to be 11 years old in the movie. Even though he's still a cub, realistically a lion his age would be considered an adult or middle-aged.
- Averted in Warrior Cats. Aside from a few inaccuracies, they age and develop just like real cats do. The exceptions to the lifespan rule are the clan leaders, who have nine lives. They measure the ages of kittens in "moons", with the kittens being promoted from "kits" to "apprentices" at six moons old (equivalent to a pre-teen human child).
- Zigzagged in We Are All Pokémon Trainers, while most species of Pokémon can live at least as long as humans, and others live shorter or even longer lives (With ghosts and inorganic mons being immune to death by old age), Pokémon generally physically and mentally mature at an accelerated rate compared to humans.
- Zig-Zagged in My Little Pony: Friendship Is Magic:
- Ponies seem to live as long as humans. On the other hand, baby ponies seem to develop very quickly, like real horses. Also, though it's debated to what extent it was intended to imply this, the very elderly Granny Smith was present for the founding of Ponyville, and that was later established to have happened quite some time ago. If taken at face value, Granny's been in the triple digits longer than most of the cast has been alive, with other generations having come and gone, suggesting that rarely, some ponies can live a great deal longer than is normally possible. The comic character Professor Inkwell is a similar case: looks very old now; looked younger when some adult ponies were children... and looked just as young for events that should be well before her time even then, but it's unclear if it's Writers Cannot Do Math at work.
- The episode "The Cutie Mark Chronicles" reveals, in a flashback, that Fluttershy as a filly resembled a real filly with long legs, compared to the others which are just smaller versions of their adult forms. Presumably, this was to illustrate what a late bloomer she was. Alternatively, it's to illustrate that she's older because she looks taller than the others.
- Many of the forms are played straight with Rex from Gawayn
- The author's note of the Animaton World Network article, Dr. Toon: Showing Their Age talks about what Wally Gator's physical age would probably be.
Author's note: As to the probable age of Wally Gator, I offer the following formulations: note