Proportional Aging

The Mandalorian: Wait. The target is a child? They said fifty years old.
IG-11: Species age differently.

— The Mandalorian, "Chapter 1"

Sometimes, when we see a race that is either immortal or very long-lived, it seems as if they age normally until approximately adolescence or early adulthood, and then stop completely. It is from this that we get the trope Immortality Begins at Twenty.

This trope is essentially the inversion, centering around a long-lived race with a proportionally long life cycle. A simple example would be to say that if this race lived twice as long as a human, then their childhood, adolescence, etc. would also be about twice as long.

In the same vein, a race who lives half as long as a human will experience a much faster life cycle, experience a childhood that's about half as long as expected.

The trope applies primarily to a creature's natural lifespan and rate of aging. A character who gains slower or more rapid aging artificially or as part of something that occurs later in life is less likely to qualify for this trope. Artificially created creatures that have this lifespan and aging built into them or artificial procedures performed very early in life can be included.

Relative emotional maturity is also an expected element of this trope, but not a required one. Generally a character who is considered among his kind to be a child at age fifty will think and behave like a child. A character whose race reaches adulthood at age five will think and behave as an adult.

Note that in real life, humans and some other great apes have proportionally long adolescences compared to the majority of species. Most animals grow to maturity as fast as physically possible and then live a maximum lifespan roughly proportional to their likelihood of being eaten, i.e. bats mature in one year and live up to 20 because they fly, deer mature in 18 months and live about ten years, bowhead whales mature in their twenties and can live over two centuries. That being said, it has been observed that the trope is generally Truth in Television, though the reality is that it's more of a case of correlating both maturation rate and maximum lifespan with reproductive quantity vs. quality rather than with each other; that is, the fewer the number of offspring produced at a time, the slower they mature and the longer their lifespan, whereas rapid breeders tend to have both faster maturation rates and shorter lifespans. This means that the common belief of one human year being equivalent to seven dog years is not quite accurate. Outliers exist, of course, making the trope more of a helpful guideline than an absolute rule.

This trope will often overlap with We Are as Mayflies and may result in Mayfly-December Romances. It may justify a Fictional Age of Majority. Compare Immortal Immaturity, when a character who is immortal acts immature and childish in contrast to their age; Age Without Youth, when a character has an extended or infinite lifespan but still grows old; and Not Growing Up Sucks, when a character is stuck in the childhood/adolescence stage and suffers in the process.

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Longer Lifespan, Slow Aging

Anime & Manga

• Elves in Drifters are stated to have a lifespan about five or six times that of humans, and it shows in their rate of maturation. The youngest elves shown are young boys who, when asked, reveal their ages as thirty-six and thirty-nine. This shocks Toyohisa, since this means they're older than he is — the Real Life Toyohisa Shimazu died in the Battle of Sekigahara being all of thirty years old (though in manga he often acts younger than his age would suggest).
• The elves in Delicious in Dungeon can live for up to 500 years, and have an appropriately proportionate lifespan. They essentially have very long childhoods, and are only barely considered adults when they reach their first century. Half-elves play with this trope, as they get the best of both worlds (at the cost of being infertile) and live for twice as long as elves. However, their lifespans are much erratic, being more physically mature than elves their age while being less mentally mature than tallmen (the world's equivalent to humans in real-life). Marcille is a half-elf, and at 50 years old, she is considered as mature as Pattadol, an 82-year-old elf looked down upon for being young and inexperienced, but it wasn't long ago that she was a contemporary of the students at a magical academy (despite being a magic tutor).
• Miss Kobayashi's Dragon Maid: Kanna (and presumably all dragons), despite being Really 700 Years Old, looks and acts like a child because biologically and psychologically she is one, even if she's chronologically very old. This has significantly contributed to the "Don't Lewd the Dragon Loli" meme that has grown up around the anime adaptation of the comic.
• Downplayed in Soul Eater concerning witches' lifespans. In Soul Eater Not!, Kim turns out to be 16, not the 12-14 year old she was implied to have been mistaken for. Apparently, their development takes longer, but not as long as their lives are (for reference, Arachne and Medusa are over 800 and still look in the prime of their life).
• Part of the premise behind Maou No Kawaii Yamada Wa Yoiko. Yamada is a thirty-three year old salaryman who one day finds himself randomly in another world full of magical beings like demon lords, lamia, and dragons. However, all of these magical creatures have a far longer lifespan such that 33 is roughly their equivalent of first grade elementary school and, because humans are unknown and everyone comes in so many shapes and sizes, nobody thinks anything of treating the adult Yamada as a child.
• In The Seven Deadly Sins, the giantess Diane acts like a fifteen-year-old and isn't taken very seriously by her coworkers (of different species), although she's lived for centuries already. In a flashback, she and a slightly older fairy visit human friends and are amazed to see that the humans got married and started a family in the few decades since Diane and King last saw them.
• Tales of Wedding Rings: Elves grow to adulthood very slowly, at which point they stop aging entirely. Nephrites is fifty-four but considered only barely an adult, so when Sato arrives to fulfill an ancient contract and marry her, her brother says she's far too young. He decides to lock up Sato for fifty years or so until Nephrites is a more reasonable age. He ignores everyone pointing out that, as a human, Sato can't handle being stuck in prison for fifty years.
• The Giants from One Piece seem to live thrice as long as humans. One giant is shown to be a young adult at 81-years old, and looked and acted like a little kid in a flashback when he was 18 years old. And the oldest giants known are over 300 years old.
• It seems to be true of the Yashahime: Princess Half-Demon youkai. In one episode, a youkai named Meifuku is already fifty years old, but looks like a child.
  • This is not the case with hanyou. They age like ordinary humans until puberty, and only then do they become long-lived.

Fan Works

• Most fanfics in the Ships Ahoy! universe run with the common fanon theory that Odd Squad agents' badges are how they are able to stay young for years and years while also growing older. Once an agent leaves Odd Squad, whether voluntarily or by getting fired, they begin to age at a normal pace.
• Where We Don't Belong:
  • Lanz tells Vanea that he's eighteen (though it takes him a minute to guess). She tells him that a Machina would be little more than a fetus at that point.
    Lanz: Hey! What the snuff are you talking about? I mean, what age is a Machina supposed to be an adult?!
    Vanea: Lanz... a Machina is a child until they are well over one thousand years old.
  • Eunie manages to avoid a similar blunder by learning about High Entia lifespans in Alcamoth, then later hearing of Melia's age first (88) before having to give an estimate of her own age (97, which is 88 plus her term number).

Films — Live-Action

• In the Alien franchise. It is believed that Xenomorphs can live for many years, even Queens and Empresses can live for many years longer than Drones and Warriors. In Aliens, it is speculated that the Xenomorphs Warrior of planet LV-426 have lived and survived on the planet for over 57 years, proving that Xenomorphs can survive for many years.
• Hellboy (2004): The eponymous character is said to age at one third the rate of a human being and thus has the physical prowess of someone at age twenty when he is sixty years old at the present time of the film.
• In Magical Legend of the Leprechauns, Mikey looks to be in his early twenties, but is stated to be "not even two hundred years old yet." We see leprechauns and fairies at all stages of life along with different people declaring themselves to be over a thousand years old.
• In the Predator series, the Predators, or yautja, can live for centuries or millennia. For example, Predator 2's City Hunter is an adolescent by yautja standards, little more than an excitable, glory-hungry teenager.

Literature

• In the Honor Harrington series, Prolong has essentially tripled the human lifespan. The treatments must be taken in early youth, and as the name implies prolongs every stage of human development. As a result, characters are Older Than They Look, with individuals in their twenties looking as potentially young as late preteens. The We Are as Mayflies overlap comes when interacting with planets or individuals who were too old to receive the prolong treatments when they became available. There's also one instance of a Mayfly–December Romance detailed in the Talbott Quandrant books.
  • In the first book the titular character is over forty in Terran years, but being a third-generation Prolong recipient she appears to be in her early twenties and in some aspects displays the emotional maturity of a teenager.
• Hobbits in Tolkien's Legendarium live slightly longer than humans (to about 120, usually; keep in mind that at the time of writing, a human passing 90 was extremely rare and when Tolkien passed in 73 at the age of 81, white male life expectancy was about 68 years and the average white expectancy for both sexes was about 72 years), with proportionate aging. Merry and Pippin, in their thirties, are considered young adults, and Frodo, in his fifties, is just shy of middle age. Hobbits are also noted to have their adolescence in their "tweens."
  • 120 is already an exceptional age for a hobbit, most of who easily pass the 90-mark, but rarely reach one hundred. It's not that the hobbits live much longer than humans; they just view age differently, and consider life to really start at 40, when all the frivolities of youth are behind them.
  • Tolkien's Elves are also an example. While they go through the diaper stage and learn to walk quickly, they only hit puberty at 50, and become fully adult at 100.
• In The Wheel of Time, Ogier can live for centuries. Loial, the one we see the most of, is ninety years old. By Ogier standards this is considered late adolescence. He is physically mature, but is considered among his kind to be emotionally immature and hot-headed. Nor is he considered old enough to leave the stedding (Ogier homeland) by himself.
• Discworld:
  • It's mentioned in Guards! Guards! that dwarf children aren't mature enough to be told about sexuality and reproduction until they hit puberty, at about age 50.
  • Reaper Man has different life forms experiencing time differently depending on their life spans. Trees have a conversation that takes seventeen years and when one is chopped down, they seem to the others to have simply vanished.
• Ian McDonald's River of Gods and related short stories/novellas feature genetically engineered 'Brahmins' who live twice as long but age at half the rate, at least physically. They actually develop faster mentally, fast enough that spending two years as a helpless infant is a source of considerable frustration and misery.
• In The Lost Journals Of Ven Polypheme, Ven's race has a life cycle about twice as long as a human's, and they age proportionately. Ven is in his twenties but is still an adolescent. The explanation given is that they don't have to grow up as fast since they have longer to live.
• The exact natural lifespan of dragons in Spells, Swords, & Stealth is not stated, but it is assumed to be very long as a centuries old dragon who serves as antagonist of the third book is an "elder", but not "ancient" dragon, while a fifty year-old dragon the NPC protagonists encounter is still considered a hatchling.
• In one The History of the Galaxy novel, a Lost Colony turns out to be the site of an abandoned alien bio-lab. The colonists became exposed to a virus that mutated them into various forms: some gained invisibility and empathy (Shadows), others became shapeshifters (Metamorphs), yet others gained Psychic Powers (Emglans), and the fourth category didn't get any powers (Chosen). However, all four groups became The Ageless. Children age normally until maturity, at which point the aging process stops. Immortal Procreation Clause is in effect as well, as it's extremely rare for new children to be born. Despite the fact that, at about 20, the colonists are physically and mentally adults, the centuries of isolation have resulted in the colonists adopting this trope. Someone who is merely 150 years old is treated as a child. When a man from The Federation crash-lands on the planet, he is treated as an infant because he's in his 30s, despite the fact that he's a trained soldier and has more combat experience than all of the colonists put together.
• In Labyrinths of Echo the inhabitants of the titular city normally live to at least about 300, and can potentially live for thousands, depending on the personal magical power,^note Juffin, for example, is about 800, and has left his humanity so far behind that the very concept of death is entirely alien to him. and they age accordingly, so Max, who is from our world, and is in his mid-thirties, was initially warned not to tell everyone his real age, lest he was tought of as a toddler. His friend Melifaro is his rough age-mate in all appearances, but is of ~130 years of age locally.
• Dragons in Birthright (2017) take about eighty years to physically mature. Mentally however, they seem about as mature for their age as humans, and are mature enough to leave their mothers at a mere six years old.
• Henry Kuttner's Hogbens. The narrator is a boy who looks and behaves like a teenager, and lost count of his age during Cromwell's times, while his younger brother is teething at the age of four hundred.
• Very common in Elcenia. Dragons, elves, and part-elves (both True-Breeding Hybrid Barashin halfbloods and Uneven Hybrid Elcenian insert-fraction-here-elves) are Long-Lived and have correspondingly long childhoods. Children of different species and different ages, but the same state of development, are described as having the same "equivalency". A bit in chapter 18 of Summons sums it up quite nicely: a girl with 3/8ths elven blood, wanting to apprentice as a witch with her dad's fiance, asks why she has to wait til she's seventeen when his existing apprentice is only nine — but the nine-year-old is all human, and so is mature enough for apprenticeship. Meanwhile, the fiance himself, a full elf, relates that he couldn't start his own apprenticeship til he was twenty-five, and the girl is quite glad that she doesn't have to wait that long.
• In Gnomes, gnome children wear diapers until age 12, and aren't fully mature until their 50s or 60s. Most marry around 100 years old, and live to about 400.
• In The Camp Half-Blood Series, satyrs age twice as slowly as humans, so Grover is in his late 20s but mentally and emotionally the same age as Percy.
• In The Immortals, Daine takes on an orphaned newborn dragon that she calls Kitten. As a dragon Kitten will be an infant for thirty years, but "infancy" seems to be defined by size rather than intelligence and most ability. Within a year of birth Kitten is more intelligent and capable than any normal animal, understanding human speech and Animal Talk and learning magic. She's carried in a sling sometimes but likes to walk. She also was born knowing the spoken dragon language, which apparently humans can't understand or Daine would have learned it at some point. The fourth book shows a couple of other young dragons, one who's two hundred and still can't use mind-speech, and one who can communicate with Daine but still has useless child wings. In Tortall and Other Lands a sixteen-year-old Kitten, who's lived surrounded by mortals, is very frustrated by being so young and knowing that she'll stay young for so long.

Live-Action TV

• The Tenctonese (aka Newcomers) in the series Alien Nation age at about the same rate as humans do until they reach their early 20s, at which point their aging slows down considerably. When Matt learns that George - who appears to be in his 30s - is actually closer to 70 years old, Matt jokingly asks if Emily is 35. George says that she is 10 and explains the Newcomer aging process in more detail to Matt.
• In Blade: The Series, pureblood vampires age extremely slowly. The most oft-seen pureblood Charlotte is about 200 years old but looks like a girl barely in her teens. Her outfit is decidedly Puritanical. However, her mindset is definitely not childlike, and everyone treats her with the kind of respect reserved for elders. The other purebloods also treat her as equals, aware of her actual age. Overlord Rusk, looking like a man in his late 30s or 40s, is stated to be over 600. It's unclear if they actually stop aging at some point. After all, turned vampires stop aging the moment they become undead.
• Doctor Who:
  • A Time Lord's rate of aging relative to their total lifespan is near impossible to determine, since when their bodies are burned out they rewrite their entire genetic codes and regenerate into a new body with new personality traits. Their aging within a single regeneration is clearer. We have seen the First, War, and Eleventh Doctors in old age, with either the statement or implication it took centuries to reach that point. The length of a Time Lord's childhood is unknown, but it's been offhandedly mentioned that Time Lords are still considered "kids" into their one hundreds.
  • At one point, the 900-plus-year-old Tenth Doctor recalls one of his earliest adventures. "I came here when I was just a kid. Ninety years old..."
  • In some fan multi-Doctor works, later Doctors consider the First and Second to be mere children, despite the fact that the First Doctor is physically older than them.
  • According to Tenth in "Time Crash", the reason First appeared to be a grumpy old man (especially in his earliest stories) wasn't because that incarnation was an old man, but because psychologically speaking, he was still at the point in life where someone wants to show how very grown-up they are, and the later, "younger" incarnations grew out of it.
• The Mandalorian: In the first episode, the Mando discovers that his 50-year-old bounty target is a baby from the same extremely long-lived species as Yoda, who died at the age of 900.

Tabletop Games

• Dungeons & Dragons:
  • D&D Dwarves for instance reach (physical) adulthood at 40 years old, are considered middle aged at 125 and can expect to live for more than three centuries baring violence. A D&D Elf is not considered an adult until he hits 110, meaning an ancient human, a Dwarf who is in the prime of his life and an Elf in the equivalent of her late teens might all have been born in the same year.
  • Depending on the source, elves are often actually physically mature around the same time humans are (most of The Legend of Drizzt takes place when the title character is in his thirties or forties), but they're not regarded as adults by other elves until they've passed their first century. Some sources has it as a combination of social attitude (elves having a more modern attitude to when people are adults) and maturing at an increasingly proportional rate the more they mature (so elven babies stop being babies not long after human babies, while elven adolescence can last for decades).
  • Played with in regards with Dragons. Dragons live for well over 1000 years, being considered wyrmlings for the first five years of their lives, and adults at around 100. Beyond that, however, all similarity to human ageing ceases. Dragons grow in power their entire lives, and the closest thing they have to getting feeble from old age is that diminishing returns set in at around 1200.
• Warhammer 40,000:
  • Space Marines age very, very slowly, since the process that turns them into superhumans begins around adolescence and takes years to complete. For example, these threeAstartes^note Note the two service studs in his temple. Each is given for a full century spent on the battlefield. are 75, 175 and 250 years old respectively. However, it's usually harder to tell, since the lack of hair hides the age difference.
  • Juvenat treatments, reserved for the Imperial elite, drastically slow down the rate of aging, allowing some recipients to be pushing two centuries and still fighting (or running away).

Toys

• Implied with the Agori and Glatorian of BIONICLE, where in order for someone to be even remotely perceived as elderly, they apparently need to be well over 100,000 years old. Gresh is younger and acts a lot like a teenager, but even he is hinted in the story to be "only" a few dozen millenia old. This is also present to a lesser extent in the main story as well, since one character is subjected to a Rapid Aging attack, which advances him 3,000 years. He's treated as no worse for wear, likely having aged the human equivalent of less than a decade.

Video Games

• BlazBlue: Celica has a special kind of soul that, along with bestowing her the ability of Healing Hands, lets her age more slowly and live for longer. Despite looking like someone in her mid-teens, she's actually a young adult. Her older self just looks like a woman in her 30s despite living for around a century.
• In Disgaea series most demons and angels seem to age about a 100 times slower than humans. So, the protagonists of the first game, Laharl, Etna and Flonne, are 1313, 1470 and 1509 years old respectively, but look and act like young teenagers.
• Final Fantasy XIV:
  • Dragons are magical in nature and can become The Ageless, but it takes a great deal of time for them to mature to such a point. Dragon whelplings are physically and mentally children for hundreds of years.
  • Viera can live to be three-to-four hundred years old but take time to mature. A Viera child won't develop their sexual traits until the age of thirteen.
• Fire Emblem: Manaketes and other long lived races tend to age, physically and mentally at a slower rate then humans or their equivalent.
  • In Fire Emblem: Mystery of the Emblem: Tiki is a 1000 years in human years, yet mentally and physically is equivalent to a ten year old human.
  • In Fire Emblem: The Binding Blade, the manakete Fa looks and acts like a young child even though she's several centuries old. It's mentioned in support conversations that manaketes just age that slowly—she will, eventually, look like an adult.
  • Different universe, same concept. In Fire Emblem: Path of Radiance and Fire Emblem: Radiant Dawn, the Laguz lives a lot longer than the Beorc, as the Beast laguz can live at least around 200 while Black Dragons can live around 1000 years. The artbook gives a straight estimate for some laguz, with Lethe comparable around 18 while Dheginsea being around 50, despite being one of the oldest laguz in Tellius, though fans have questioned if that information is canon to the final script due to contradictions with in-game statements. Branded are also long-living and their appearance may not be indicative to their age. Micaiah still look like a young girl despite her closest friend, Sothe, growing up quite noticeably and Stefan (also a Branded) once point out that Amy (Largo's and Calill's adopted daughter) is Branded and still look like a little girl. However, dialogue between Stefan and Soren in Path of Radiance implies that the Branded instead experience Immortality Begins at Twenty by aging at the Beorc rate until they turn sixteen and it slows to match their Laguz ancestry; this dovetails with Micaiah's appearance, as she appears around sixteen while the timeline places her chronological age between twenty-three and twenty-seven.
  • Fire Emblem: Awakening, Tiki's expy, Nowi is 1000 years in human years, yet a child in dragon years, as a result she is mentally and physically a child. The English script tries to hide this as Nowi is marriageable to grown humans, but even there Nowi's daughter Nah says in the Harvest Scramble DLC that Manaketes who look like children would have the mental capacity of a child.
    • Tiki herself reappears in Awakening as well. Sure enough, it's been over a thousand years since her last appearance, and she now looks like an adult in her 20s or so.
• The Legend of Zelda:
  • Downplayed and played with concerning the Zora in The Legend of Zelda: Breath of the Wild. They live to be a bit over 200, and the Zora princess Mipha notes at one point that Link, a Hylian presumably around the same age as her (17), looked grown up faster than her (he's One Head Taller than her despite adult Zora being One Head Taller than the average Hylian). There's also Finley, a Zora girl who appears to be a short child but complains about not yet reaching that final growth spurt and also speaks in a very formal and adult diction, indicating that she's in her mid-teens at the youngest; she eventually hooks up with a Hylian guy who appears to be in his 20s at the oldest, and her mother doesn't see anything wrong with this. This is in contrast to Zora princess Ruto from The Legend of Zelda: Ocarina of Time, who seems to grow up at the same rate as Link.
  • The Champions' Ballad DLC confirms that Sidon, Mipha's younger brother, was born during Mipha's lifetime, despite her having been dead for a century in the present. Since Sidon is a child in his flashback with her, and a not-particularly-old-looking adult in the present, the implication is it took him most of the century to fully mature.
• Mass Effect:
  • The Asari have an average lifespan of around a thousand years and age very slowly, their cultural life stages also reflect their long lifespan as seen with Liara, who despite being 106, is considered the human equivalent of a young adult in their early 20s. Generally, the asari have three distinct phases of life, the Maiden stage from puberty until around 350, the Matron stage in the middle when they begin to settle down and have children, and finally the Matriarch stage from around the age of 700 until their deaths.
  • Zig-Zagged with the Krogan, thanks to their unique regenerative biology, they can live about as long as the asari if not longer. However, because they're a Proud Warrior Race from a Death World who constantly hire themselves out as mercenaries, most of them never make it past a century before they die. As such, krogan who are long lived are considered extreme badasses for being able to survive constant fighting for so long. The prime example being Wrex, who is several centuries old and is implied to be a veteran of the Krogan Rebellions which occurred about a thousand years ago.
• In Sword of the Stars, Liir reach maturity at the age of fifty and live for centuries, possibly millennia if they escape gravity's influence on the Square-Cube Law.
• Trials of Mana: The half-elf Charlotte is fifteen but looks and behaves like a human five-year old, indicating that she ages at one third of the rate of a human, though it is also suggested that she would be more emotionally mature if she were treated according to her chronological age.
• World of Warcraft: Draenei live for tens of thousands of years, but take a significant amount of time to mature. When the orc Durotan returns as an adult to a draenei village he came to as a child, he finds the same girl he saw there before having barely aged at all.
• Xenoblade Chronicles 1:
  • The High-Entia are a winged elf-like race with a lifespan going into at least the 400s. Their physical ages are proportionate to their chronological ones. High Entia children have ages in the 30s-60s while young adulthood seems to be around the mid-late 100s and old age being the high 300s.
  • The Machina are another example, having lifespans going well into the thousands and seemingly aging proportionate to them. However, being as they're machines/cyborgs it's unknown if they actually age as biological beings would.

Web Comics

• In Irregular Webcomic!, elves are said to breastfeed for 30 years, teethe for 20 years, throw tantrums for 100 years, and don't take to toilet training until they're about 200. As Alvissa puts it, "elves invented effective contraception before we could use fire."
• The Order of the Stick:
  • Elves are shown to experience this. Vaarsuvius' two children are 26 years old. For elves, this is the equivalent of kindergarten-age. In the prequel On the Origins of PCs, V mentions spending 20 years in diapers as a downside to slower aging.
  • Discussed when the long-lived half-elf schoolboy Pompey has to accept Nale, a human, as his leader:
    Pompey: Wait, you're only 21? Jeez, I'm 43, why the heck am I letting you call me "Kid"?
    Nale: It's not the years, kid, it's the mileage.
• Kayoss in L's Empire age about 100 times slower than humans. Although they grow proportionally to that of a human, they don't reach sexual maturity until they're in their 2000's.
• Darwin Carmichael Is Going to Hell: Darwin's "pet" manticore Skittles is over 2,000 years old but acts like a little kid. Until the Apocalypse starts and the background magic causes him to go through puberty rapidly.

Web Original

• Scientifically Accurate Ninja Turtles notes that since turtles live for two centuries, "teenagers" would have the minds of seven-year-olds.
• Serina: The daydreamers are a sapient species of large orca-like marine bird that possess an average lifespan of around 130-140 years. As such they reach sexual maturity in their late 20s and lose their fertility in their 70s.

Western Animation

• Wonder Woman in DC Super Hero Girls is 317 years old, but her mother isn't just being coddling when she refers to her as an adolescent—that's why she's so much shorter than the adult Amazons.
• While the total lifespan of the titular Gargoyles is not stated, in the Season 2 episode "Grief" Goliath explains that Gargoyles age at half the rate of humans because they don't age while turned into statues during the day. This can be seen when Goliath and Eliza meet Tom. Tom was a child back in the Manhattan Clan's original time and helped care for the unhatched Gargoyle eggs in the castle rookery. When they meet Tom as an adult, he's old enough to have significant amounts of gray in his hair, but the Gargoyles he helped nurture are still adolescents.
• Steven Universe:
  • Steven may have something like this going on—he's the first gem/human hybrid, so no one's sure how he ages. Eventually, it's shown Steven aged normally for eight years, seemingly stopped for six, but then suddenly showed signs of reaching puberty (a single facial hair). However, another episode suggests he may change his age unconsciously or even at will, thus he might be able to overcome this disadvantage. By the time he's sixteen in the movie, he does in fact look almost fully grown.
  • Word of God has confirmed that Lion and Lars are not outright immortal, but rather will age very slowly compared to other members of their respective original species. This explains Lars' very slow heartbeat felt by Steven after he died and was revived on Homeworld. At least one of them was almost fully grown by the time they Came Back Strong, negating most of the downsides of this.
• In the special episodes of Wakfu, Yugo discovers his Dragon Ancestry has made him Long-Lived, but is displeased that he still looks ten as he's reaching his twenties.
• Invincible (2021): Omniman reveals that Viltrumites have very long lifespans as a result of aging very slowly. This even extends to his son, Invincible, despite the fact he is technically half-human/half-viltrumite, Omniman explains that Invincible is almost pure Viltrumite because of how genetically similar humans are to them and the fact that Viltrumite blood is dominant.

Real Life

• The Greenland sharks don't reach sexual maturity until they are 150 years old and some individuals seemingly can live up to 500.

Shorter Lifespan, Fast Aging

Anime & Manga

• Half-foots in Delicious in Dungeon reach adulthood at 14 and have an average lifespan of 60 years, though their short stature makes it hard to tell. The rest of the party tends to treat half-foot Chilchuck like a child even though he's 28 and has three adult daughters, everyone is shocked when a changeling mushroom turns him into a tallman (human) who looks middle-aged.
• Windermerans in Macross Delta are a Human Subspecies created by the Protoculture to have incredible physical abilities at the cost of a radically shortened lifespan. The average Windermeran lives for barely 30-35 years. It's played with in that it mainly concerns their social age, rather than biological. Frejya, for example, is fourteen, and looks it, but is considered an old maid and enters the story to escape an Arranged Marriage with a potential suitor who, she believes, she is Better as Friends with. Helman is already an old man by their standards at 33, with confirmed grandchildren, but he doesn't look any older than that.

Arts

• The traditional illustrations of Baby New Year, who is a baby on January 1st and ages into an old man by December 31st, when he dies to be replaced by a new Baby New Year.

Fan Works

• Vow of Nudity: Swiftstride shifters (of whom Fiora is a member) reach young adulthood at 10 and usually live less than 70 years.

Films — Animation

• In Fantastic Mr. Fox, the concept of fox-years implies that foxes age six times as fast as humans. Ash is two years or twelve fox-years old, and is about as mature as a twelve-year-old child, while Mr. Fox is seven years old (which would be forty-two fox-years), and has a midlife crisis.
• Madagascar starts with Marty the zebra suffering a Hollywood Mid-Life Crisis at his tenth birthday.

Films — Live-Action

• The Alien Drone from Alien, according to Word of God, the Drone had a short life expectancy of a few days, the Alien was dying in the shuttle, after he creates his own nest in the Nostromo. He was looking for a safe hiding place in the shuttle to die alone, since he had already fulfilled his objective.
• Clone troopers in Star Wars are modified to age at twice the rate of regular humans, allowing them to become combat ready in half the time. However, it comes with the drawback of halving their lifespans; which is why they've mostly been phased out in favor of regular human recruits by the time of the Original Trilogy. As of A New Hope the youngest clones are chronologically 19 years old; which means they're pushing 40 biologically.

Literature

• Animorphs has the slaves of the Yeerks include the Hork-Bajir. The Animorphs help two of them escape early in the series; one is pregnant at the time and gives birth to Toby, who Tobias first sees when she's about four feet tall. He reflects that Hork-Bajir don't live as long as humans do so it makes sense if they grow up quickly. Within a year of her birth Toby is helping her parents plan raids to rescue more of their own kind (though she's special, as a Seer with far more intelligence than is normal). Within two years, by the climax of the series, she's only a few inches shorter than the seven feet of adults. It seems like it does take another year or two for a Hork-Bajir to be truly fully grown and adult, as at the end of the series - when she's four years old - Tobias remarks on her being all grown up.
• A Christmas Carol: As Scrooge and the Ghost of Christmas Present go about watching people celebrate the holiday, Scrooge is surprised to notice that the Ghost is rapidly aging. The Ghost explains that his lifespan is only a single day and ends that night.
• In the Star Wars prequels, clone troopers age twice as fast as baseline humans. Expanded universe materials mention they also live half as long, and an attempt to fix this is used as a subplot in the Republic Commando Series.
• Reaper Man has different life forms experiencing time differently depending on their life spans. Elderly mayflies at sunset are seen reminiscing about how the sun was properly yellow and high in the sky when they were young.
• The Beyonders: The drinlings have a lifespan of only about two to three years, and every aspect of their life cycle is sped up proportionately (they reach maturity in only a few months, can gain muscle from exercise at an almost visible rate, etc). The (human) main characters spend a few months in the company of some drinling allies, and it is occasionally mentioned how surreal they find it watching the drinlings go from teenager-equivalent to young-adult equivalent in only a few weeks.
• The Nomes in the Nomes Trilogy live for about ten years (assuming nothing eats them), and all references to their age, or even their experience of time, assumes a year for them is roughly equivalent to a decade for us.
• Snowdrop in Pale is an opossum given a human form to assist Avery Kelly, but after a few months Avery realizes that Snowdrop has gone from looking like her kid sister to being nearly the same age, since opossums only live two to four years.
• In the Garrett, P.I. series, Melondie Kadare the pixie lives out her life from an adolescent with her first crush to a middle-aged drunkard with grown children over the course of a few books. It's unclear how fast she'd have died of old age, had she not passed out in the street and been run over by a cart, first.
• The Kolnari of The Ship Who... are a Human Subspecies who are largely Immune to Drugs, poisons, and most diseases, as well as having very fast reflexes and high strength, and tend to be very beautiful. The downside is that they complete puberty by age eight, in their forties Rapid Aging sets in and ruins their looks, and in their fifties they may still be active but are regarded by their fellows as senile. This is a setting where most humans are quite Long-Lived, too. To compensate for their short lifespans, their constant infighting, and their Too Dumb to Live policies about the sick or injured, they're also Explosive Breeders giving birth after four-month pregnancies to multiple infants at a time.

Live-Action TV

• Star Trek: Voyager: The Ocampa only live 9 years, and by age 1 are fully adult.

Tabletop Games

• Dungeons & Dragons:
  • Half-orcs reach adulthood at 14 and are considered venerable at 60 with a max age of 80, humans are adults at 15 and venerable at 70 with a max lifespan of 110. Full blooded orcs have it even worse, reaching adulthood between the ages of 11 to 14, becoming middle-aged at 17, are considered elderly at 23 and are venerable at 35. They technically can live up to 50 years, but an orc living past 45 is unheard of without some sort of magical assistance.
  • Aarakocra have it even worse, being considered mature by 3 and rarely living longer than 30.
  • Quicklings, a hyper-accelerated type of fae, mature in under a year and expire of old age by 15.
• In Shadowrun all metahumans are legally considered adults at 18, but orks are physically mature at 12 and live 35-40 years.

Video Games

• Mass Effect:
  • The Salarians live for only forty years on average and accordingly mature faster. Mordin, who is considered geriatric at thirty-eight, mentions that his nephew is a tenured professor at sixteen and that this is considered normal for his people.
  • The Vorcha have it even worse as they only have an average lifespan of twenty years. As a result, not only do they mature extremely rapidly, they also breed extremely rapidly. These traits, combined with their lack of intelligence due to having such short lives, has led most of the other species to consider the vorcha barely more than animals, and they are commonly compared to rodents and other pests due to their tendency to cause overpopulation.
• In Sword of the Stars, Zuul grow to full size in a matter of months and usually die of natural causes before they turn 40.
• The hozen of World of Warcraft are a very short lived race, having lifespans of about twenty years. Their elders are typically around thirteen or fourteen years old.
• Winston, Overwatch's resident uplifted gorilla, is 29 years old but comes across as middle aged. Real life gorillas live about 50 years.

Web Comics

• In Our Shadow: Most of the small mammals that evolved sapience after humanity's extinction reach adulthood in less than a year and live for a decade or so.
• Kevin & Kell has played this for laughs with actual mayflies. Such comics often show them being born and dying within the course of the same strip.
• The Order of the Stick: Goblins expect to die of old age by 50, in the Start of Darkness prequel book we see Redcloak's younger brother Right-Eye go from a small child to a grey-bearded adult over the course of thirty years, even while Redcloak's Crimson Mantle keeps him looking like a teenager.
• In Public Humiliation, pookas mature in about a year, their lifespan is never given specific numbers but it was short enough for Boo to break up with her longer-lived boyfriend for fear of leaving him when he still had his life ahead of him. However, it's discovered that semigods like Lan's progeny, including Boo, have the proportional equivalent to Immortality Begins at Twenty, and they can pass that longevity onto their mates.
• In TwoKinds, keidran can live up to their mid-twenties and are adults around age 8 or 9 (about a third of their lifespan).

Western Animation

• The Petalars in ThunderCats age from childhood to death by old age in a single day. From their perspective, it feels like a long life.

Real Life

• Some other great apes have life cycles proportionally similar to humans, but shorter lifespans.
  • Gorillas often reach maturity at 9-12 and typically live to 40 in the wild, 50 in captivity, with 60 as the record.
  • Chimpanzees are mature at about 10 and have reached their 60s in captivity, with at least one specimen who lived to 78.
  • Orangutans are sexually mature at 15. There's little data on their potential longevity, but one has been recorded living to 55.

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