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Whale Egg

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Aww, look, a newly-hatched baby rhi—hey, wait a minute...

Lisa: Wait. Rhinos don't come from eggs.
Homer: What did you just see, Lisa?
Lisa: I know, but—
Homer: What did you just see?
Lisa: Hmph.

In the natural world, living creatures have a myriad of ways of bringing more young into the world. Some produce thousands of eggs and young that grow quickly but only a few make it to adulthood. Others invest huge amounts of time and resources to develop and take care of only a few at a time.note 

In fiction, it's often simplified into laying eggs, even if the biology of the creature in question should indicate otherwise. This is very useful in bypassing the complications of an Interspecies Romance and the Squick of a live birth, which is also why it's a common implementation of G-Rated Sex.

Popular Mons trope, as pretty much every Mons series uses it. Especially the ones that originate in video games, where it also serves to simplify the breeding mechanics — see Hot Skitty-on-Wailord Action. May also overlap with Cosmic Egg, if the egg in question produces or is laid by a deity. Compare Egg-Laying Male if the species has the ability to lay eggs, but is male. Contrast with Pregnant Reptile, in which a non-mammal reproduces the mammal way.

Whales don't lay eggs; they're mammals that give live birth.


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  • An advertisement for the dog food Nutro opens with a puppy hatching from an egg. They are also shown later in the ad growing on trees and being found inside fruits and vegetables.
  • One cat food commercial in Thailand featured cats hatching from eggs.

    Anime & Manga 
  • Digimon Adventure: The Digimon are asexual so the eggs actually spawn from the remains of dead Digimon. Since the Digimon that "spawn" from this act are actually the same individual Digimon that died, it works as a Disney Death and Resurrective Immortality. Though several cases could result in real death for good, such as fights taking place in the real world, or if someone manages to invent a device to get rid of that feature. Digimon can also be deleted, though the specifics are vague and might lead to Came Back Wrong instead. The first season is the only one to address this specifically, with others either leaving it ambiguous or not addressing it at all.
  • Doraemon:
    • Doraemon: Nobita and the Birth of Japan features Doraemon's Life Creation Set, a gadget that can create artificial life that's later hatched from eggs — one of those constructs being a Pegasus named Pega.
    • Doraemon: Nobita and the Spiral City have an Egg Factory in the titular city which creates eggs where their inhabitants - Living Toys — are hatched from. Even toys of mammals, including two particularly intelligent stuffed pigs named Pibu and Popi, are created from these eggs. Justified since they're, well, toys.
  • The fifth chapter of Eastern and Little Nature Deity revolves around a giant mysterious egg. Most characters assume it's from a cat youkai.
  • Fairy Tail: Happy hatched from an egg. Supposedly, so did his Romantic Interest Carla. Their species, for reference, resemble bipedal cats. Their eggs are also larger than full-grown members of the species, in case the fact that they technically aren't cats made eggs seem plausible.
  • Tenchi Muyo! has Ryo-Ohki, a cat/rabbit creature who can turn into a spaceship and a humanish girl, hatch from an egg. In addition, Ryoko joked that the egg was hers and that Tenchi was the father, but it later turns out that, in a really convoluted way, the egg came from Washu.
  • Although Domo appears to be mammalian in nature, his first appearance was being hatched from an egg.
  • Dragon Ball: Namekians are asexual aliens that reproduce by spitting eggs infused with some of their life force.
  • Pandemonium Wizard Village: Variants can be born out of eggs, even if the parents are mammalian. Domika was hatched from one and has a belly button, though that sort of thing isn't the strangest thing variants can be born with.

    Comic Books 
  • Skrulls lay eggs. Johnny Storm, who was briefly married to a Skrull named Lyja (long story), was greatly disconcerted when she... well, laid an egg. It turns out it wasn't his, though. Which was... good news and bad news at the same time, kinda.
  • This was subverted in an Archie Comics story, where Jughead had to take care of what he thought was a kangaroo egg in Professor Flutesnoot's laboratory, until Mr. Weatherbee showed up and informed Jughead that kangaroos don't lay eggs. When the egg did hatch in the end, it turned out to actually be an ostrich egg.
  • One of Toph's disciples in the Avatar: The Last Airbender comics was surprised to learn Toph had human parents. Up to then, she'd assumed Toph had willed herself into existence from a boulder.

    Fan Works 

    Films — Animated 
  • When Mary asks Max how babies are made in Mary and Max, he says his mother told him that babies hatch from eggs laid by a rabbi.

    Films — Live-Action 

  • The Easter Bunny, according to some. They're not all chocolate, you know. Mythologically, the bunny originated as an egg-laying animal; being able to lay eggs once a year was a form of consolation (the day was only later retconned to Easter). Of course, in the original myths the bunny wasn't Peter Cottontail. While most modern versions of the character don't actually produce the eggs from their own body, this hasn't stopped the tradition from confusing kids for centuries anyway.
  • In Classical Mythology, Leda, the human queen of Sparta, has sex with Zeus in the form of a swan, and later with her human husband Tyndareus. She lays two eggs, one containing Castor (usually the son of Tyndareus) and Polydeuces (son of Zeus), the other containing Helen (usually daughter of Zeus), later of Troy, and Clytemnestra (daughter of Tyndareus). The parentage and pairing of these children is not consistent, but the story always involves two completely normal human children hatching from eggs.
  • In Korean Mythology, many founding heroes of ancient kingdoms (three kingdoms) were born from an egg. Here are examples:
    • Go-Jumong (King Dongmyeong), founder of Goguryeo Kingdom, was born as a large egg that his mother (Lady Yuwha) laid. His stepfather (King Geumwha) took this as bad omen and tried to get rid of it, but all attempts failed (when it was thrown into wilderness, fierce animals and birds kept it warm; and even the strongest warrior couldn't break its shell open). Finally Jumong was born, and he soon grew up to be a master archer and charismatic hero (which is not surprising, given that his father is the Sun god Haemosu).
    • There's also Pakhyeokkeose, Seoktalhae and Kimalji, three founders of Silla Kingdom. Plus there's King Kim Suro, founder of Gaya (a minor kingdom that was later absorbed into Silla).
  • Chinese Mythology: Pan-Ku, the first living being, hatched from an egg that became the sky and the ground.
  • In Pacific Mythology, the Earth goddess Papa laid an egg on an island or archipelago known as "Kahiki". It contained the goddess Hi'iaka, who was carried to Hawaii in the egg by her older sister, Pele, and Born as an Adult.

  • The humanoid Red Martians in Edgar Rice Burroughs John Carter of Mars novels lay eggs that are then hatched in incubators. They are somehow cross-fertile with humans. (Biologist and SF consultant Jack Cohen has speculated about Carter's shock when he encounters Dejah Thoris's eggshell-producing apparatus.)
  • Happens as a (disturbing) twist at the end of the Goosebumps book Egg Monsters from Mars. The protagonist, a 12-year-old boy, is impregnated by the titular monster and lays an enormous egg in the last page.
  • Subverted in Tamora Pierce's short story Nawat. The titular character's wife does not lay eggs, despite her fears. Instead, one of the babies takes after her crow-to-human shapeshifter father by eventually growing some feathers.
  • At least two of the races (namely, the chiropteran Aeries and the near-human Walkers) in Laurie J. Marks's Children of Triad trilogy seem to be monotremes.
  • Played with in Dr. Seuss' Horton Hatches the Egg: Everybody flocks to see the (male) elephant sitting on an egg, but it was actually laid by a bird who asked Horton to egg-sit (though it's unclear if the mother planned to come back). At the end, this trope turns out to be a case of Lamarck Was Right, as the egg hatches into a winged elephant.
  • Journey to the West: Sun Wukong technically hatched from a rock, but it's often referred to as the Great Stone Egg.
  • The Last Dragon Chronicles: Descendants of Guinivere hatch from eggs. It Makes Sense in Context.
  • Discussed and played for laughs in The Last Dogs. In the final book, Tiffany the raccoon boasts about how she'd snuck up on bobcats laying eggs, and about how she knows about bears laying eggs and the baby bears swim immediately after "hatching". Rocky is very skeptical about this and calls her out on it several times.
  • In A Swiftly Tilting Planet, Winged Unicorns hatch from eggs—but only the ones who are also Time Travelers.
  • In the Leviathan Trilogy, the perspicacious loris is hatched from an egg and, judging from what one character says, many fabricated beasts are "born" this way.

    Live-Action TV 
  • The atom bomb that appears in the lads' house on The Young Ones turned out to be an airplane egg, which hatched a tiny balsa-and-rubber-band toy plane at the end of the episode.
  • When kobold Pumuckl and his "owner" (for the lack of a better word) were in the zoo, Pumuckl found an ostrich's egg and thought it was an elephant's egg.
  • Mork & Mindy: Mister Seahorse himself, Mork from Ork. Because Orkans age backwards they're born resembling middle-aged humans, so the eggs they emerge from are huge by the time they hatch.
  • Prehistoric Planet features the Adalatherium, a badger-like Mesozoic mammal. It's first introduced inspecting a clutch of eggs in a burrow, with the narration implying and suggesting that it is raiding a dinosaur nest as early mammals are stereotyped to do, but as it turns out... they are her own eggs. Adelatherium, like most non-eutherian Mesozoic mammals, were egg-layers. Egg-laying used to be far more common in Mesozoic mammals.
  • Odd Squad: In "O is for Opposite", Delivery Doug has a goat assistant named Randall, who lays eggs that Doug then uses to make the egg salad used in his sandwiches. When he tells Olympia and Otis this and explains that Randall laying a single egg takes a long time, Olympia asks him why he doesn't just use chicken eggs, which causes him to have a realization as he lays Randall off from his job.
  • In Once Upon a Time, Dwarfs are a One-Gender Race who hatch from eggs, fully grown and clothed.
  • In The Orville, Moclans reproduce by laying eggs.
  • That '70s Show: In "Hyde's Birthday", Kelso sneaks into the Formans' garage to get a saw, and when he gets caught by Red, he tries to bluff his way out, and that goes about as well as you'd expect, leading to this amazing line:
    Kelso: There's a rabbit stuck in a tree and I want to return that rabbit to the wild, so it can lay its eggs.
  • In the Ultra Series, some kaijus, despite being hatched from eggs, have mammalian traits. Such as the elephant-like Sartan from Return of Ultraman and the lion-based Gora from Ultraman 80.
  • In the second episode of The Mandalorian, the titular hero is sent to a cave to retrieve an egg for some Jawas. He is confronted by a huge woolly rhinoceros-like creature. With an equally-woolly egg, as it turns out.

    Puppet Shows 
  • The Wubbulous World of Dr. Seuss: In the prologue to "The Song of The Zubble-Wump", the Cat in the Hat is seen incubating some eggs that house mammal-like creatures, including a cow (which he describes as "udderly" ridiculous), a cross between a cat and a dog, and a tiger, whom he names "Benjamin" when he hatches after the commercial break. In the epilogue, the Cat ships out eggs that have cat tails protruding out of them and wear tall red and white striped hats, not unlike his own.

    Tabletop Games 
  • Dungeons & Dragons:
    • Gith are a humanoid race with no ouward reptilian or avian traits and who, in some editions, explictly descended from human ancestors within historic times. They reproduce by laying eggs.
    • A sylph is an Always Female fey who looks like a beautiful elf woman with dragonfly wings. To bear a daughter, she has to seek a mortal suitor, usually elf, human, or Halfling. Despite this, the child, described as a "baby girl with wing buds", hatches from an egg that the sylph keeps in a special nest, guarded by an air elemental.
    • The game also gives this trait to pretty much any beast that has bird-like wings, no matter how much it resembles a mammal otherwise. Griffons, hippogriffs, and pegasi all hatch from eggs, although 5th edition describes pegasi as giving live birth instead. It's mentioned in the description for avorials, or winged elves, that there's an in-universe belief that this is true for them, but it is not.

  • The Hatchimals line revolves solely around this trope. As such, all the animals, regardless of appearance, hatch from eggs. This even includes pixies.
  • Furby: Furbies also hatch from eggs. Appearance wise, they're like if you crossed a koala with a penguin.

    Video Games 
  • Bomberman: Blowing up a soft block in later games will sometimes yield a giant egg. Touch this egg, and an adorable kangaroo hatches. (Averted in Saturn Bomberman, because they're dinosaur eggs instead.)
  • Billy Hatcher and the Giant Egg has them all over the place, generally used as weapons and movement aids. Things that can hatch from these eggs include tigers, butterflies, winged fire-breathing hippos, and Sonic the Hedgehog himself, among who knows what else. It's even lampshaded when an NPC chick wonders who or what laid all of these eggs to begin with.
  • Spore: Every single creature hatches from an egg, even those who are well past gaining sentience.
  • Final Fantasy Tactics: Every monster that joins you reproduces asexually by laying eggs. Makes sense for the Chocobos, gets strange for the cats, skeletons, trees, and pigs.
  • Lightning Returns: Final Fantasy XIII: Fuzzy Sheep are discovered to lay eggs. An NPC who is a biologist reminds us about the platypus.
  • Creatures: The Norns and Ettins look mammalian (and one popular third-party breed for the second game was able to nurse their young,) but all three creature types lay eggs (of course, they were all genetically engineered by an entire species of extremely absent-minded scientists, so they don't necessarily have to make that much natural sense). The scientists were also so squeamish (canonically!) as to have to invent kisspopping, so whatever process results in the eggs, they likely found it more emotionally palatable than seeing a miniature version of the Norns (et. al.) being shoved out of an orifice of another.
  • In earlier Dragon Quest Monsters games, your monsters laid eggs, regardless of what they were.
  • I Was a Teenage Exocolonist: Hopeyes lay eggs despite being the Fantastic Fauna Counterpart to various rodents. However, Vertumnan wildlife has quite porous lines between plant, fungus, animal and mineral, so a being analogous to a mammal laying eggs is nowhere near the strangest thing the planet is harboring.
  • Pokémon:
    • Every single Pokémon ever. Including the whales. And the plants. And the rocks. And the ghosts. And the robots. And the eggs. And the god too. Apparently, the first thing to ever exist was the egg of Arceus! And the age-old question is put to rest.
    • A diary entry in the Cinnabar laboratory states that "Mew gave birth," making it seemingly the sole exception. Mew is also among a subset of Pokémon that are functionally genderless and never lay eggs. On the other hand, the birth may or may not have happened, as every piece of information on Mewtwo's origins are contradicted somewhere else. It could have been just a metaphor, since it is said that Mew's genes were used in the creation of Mewtwo. The journal explaining Mew giving birth was also during a time where there were no breeding mechanics at all until Pokémon Gold and Silver. Pokémon Let's Go, Pikachu! and Eevee! retcons the journal to say Mewtwo was created in an artificial growth chamber.
    • The question of how any particular mon couple mates and lays eggs is sidestepped. To breed two creatures, you leave them at "daycare" together; eventually one of the daycare-takers will give you an egg, saying that they "don't know where it came from, but your Pokémon had it." There's a trainer class of "Pokémon Breeders," but somehow no one in-universe seems to know how the eggs are produced. Considering some of the Pokémon that can breed together, this may be a good thing. Pokémon HeartGold and SoulSilver finally seem to address this issue in a scene involving Arceus at the Sinjoh Ruins: every time a Pokémon egg comes into the world, it's literally because Arceus created it.
    • And finally subverted by an NPC in Coumarine City in Pokémon X and Y: according to him, Pokémon eggs aren't really eggs at all, and instead are sort of like a "cradle" for newborn Pokémon to develop in until they're strong enough to survive in the world. This is also why a majority of them are Born as an Adult. That said, it brings up questions about how different species can breed since some would logically lay eggs and others would give birth, but can reproduce together anyway.
  • The Facebook game Fish World lets you gain new creatures for your virtual aquarium by buying "Fish Eggs". The, err, "Fish" include everything from crabs to turtles to squid to, yes, Whale Eggs.
  • Collecting chicken-style eggs that will hatch out into all sorts of creatures — birds, mammals, frogs, fish, bugs, trees, VAMPIRES — is the whole point of the Facebook game Hatchlings.
  • The plot of The Legend of Zelda: Link's Awakening is to break the ostentatious egg of the Wind Fish, which is essentially a gigantic, telepathic whale with disproportionately tiny wings (Also to fight evil Kirby clones, but that's irrelevant at the moment). How the egg was actually laid by the (seemingly male) Wind Fish and why it houses a mysterious labyrinth can both likely be explained by the whole adventure being All Just a Dream. Specifically, the Wind Fish's dream, which Link is trapped in.
  • The Sapling: Starting with the Flight and Flight update, players are capable of choosing whether or not individual species lay eggs or give birth. Since this is a variable independent of all other factors, there's nothing keeping you from making mammal like creatures that lay eggs.
  • Super Mario Bros.:
    • Ever wonder how Bowser got his kids in the first place? Now we know why, considering if Bowser Jr's theory of how he was born was true...
    • Super Mario Galaxy has Dino Piranha, a plant-dinosaur hybrid that is born from an egg, and Super Mario Galaxy 2 has Peewee Piranha, another plant-dinosaur hybrid born from an egg.
  • In Minecraft, in creative mode, any and all of the mobs can be spawned with eggs, even piglins and ghasts and villagers.
  • Played with in the Adventure Island series, where you can get items from eggs, as well as dinosaurs (predictably). Who, or what, lays item eggs? Oviparous mammals, oviparous robots, and oviparous slime creatures in Pokémon figure into Cracked's #27 Science Lesson As Taught by Famous Video Games.
  • There is an entire genre of games for tablets and mobile devices where the player builds some type of haven, fills it with decorations and/or enclosures, then breeds and/or feeds various monsters and critters. These frequently show the monsters hatching from eggs, even when the monsters look mammalian, such as in My Singing Monsters.
  • In the Guilty Gear series, newborn Gears apparently hatch from eggs. This explains how Justice's daughter Dizzy was born years after her mother's demise.
  • Putty has a Mutant Chinese Chicken which lays sumo wrestler eggs.
  • Legend of Mana lets the player raise and train their own pets, all of which hatch from eggs, even sentient wooden toys and mimic chests.
  • In MapleStory, one quest has you collect eggs from Chronos, Tick-Tocks, and Timers, and a related quest has you raise a baby Timer from an egg. While the last one resembles a bird, it and Tick-Tocks are Clockwork Creatures, and Chronos are undead beings; how any of them can even reproduce, much less from eggs, is a mystery. (Making it even weirder, the quest where you raise the baby Timer requires you to feed it Springy Toy Worms, and it's unlikely most living beings could eat such things.)
  • The Facebook game Ovipets, where you breed horses, cats, and wolves, among other animals, all subsequently lay a egg. This is probably so it can have the game mechanic of turning other people's eggs to collect coins, and also give them a way to encourage you to keep coming back to the game; you have to turn the egg every so many hours by clicking on it for it to hatch, or have someone else do it.
  • Moshi Monsters has a species called Silly Snufflers, which are basically like miniature, yellow, polka dot elephants, yet they come from eggs.
  • All the animals in Parkasaurus hatch from eggs, including the fully-aquatic reptiles in Sea Monsters and the mammals in Prehistoric Wonders, who gave live birth in real life.
  • In Elona, any follower you have can be put in a ranch, where it will create eggs and milk regardless of species or gender. Even humans, machines and undead will produce these items. Newly-created ranches have a book that Handwaves this:
    Any animal assigned to be a "breeder" will stay on the ranch, and, in time, produce milk, eggs, shit, and other bits. And no, I am not going to try to explain how mammals will lay eggs or how exactly you milk a twenty-ton firebreathing lizard. I don't rightly try to answer those sort of questions and frankly, neither should you. Just accept the fact and move on.
  • Warframe: Kubrows on Earth are shown to hatch from eggs, despite looking like canines. There is a justification in that the Kubrow were genetically engineered by the Orokin.
  • The titular dogs in Wobbledogs hatch from eggs.
  • In Fallen London, the Fictional Holiday of Whitsun involves collecting eggs and hatching them. Aside from the London-typical unsettling pets, bizarre companions, and freaks of nature, you can also hatch items of clothing.

    Visual Novels 
  • South Scrimshaw: Played with. The Brillo Whale calf that the documentary focuses on is shown being born from what initially appears to be an egg, but is in fact a kind of external placenta attached to his mother. Presumably this is an adaptation to prevent the birth from being impeded by whatever external organisms are growing on the mother while still allowing her to keep her unborn baby with her.

    Web Animation 
  • Homestar Runner: The Strong Bad Email "flashback" tells the story of Homestar and Strong Bad meeting during a quarrel over a giant egg, which turns out to contain "a lifetime supply of fish sticks...and a The Cheat!" For reference, The Cheat is some kind of furry, vaguely rodent-like creature that serves as Strong Bad's lackey.


  • In Spec World, a parallel universe where dinosaurs survived and the Cretaceous extinction never happened, many of the lineages of egg-laying mammals survived as well. There are creatures resembling rats or mice but lay eggs, as well as many platypus relatives filling niches of badgers, weasels and raccoons. A strange aversion is the whale-like platypus called the Moby Duck, which independently evolved live birth from the placental mammals.
  • In Hamster's Paradise, the original sketches depict a species of bird-like hamster that had re-evolved the ability to lay pseudo-eggs. Starting off by producing undeveloped young like a marsupial, it eventually evolves the ability to contain the newborns within an amniotic sac where they can develop further outside the mother's body, and emerge as a fully-developed fledgeling.
  • Nobody Here: At the end of the animation in "Dodo", Jogchem (the author, a human) hatches out of an egg fully grown.
  • Sylestia: Exaggerated Trope. Every female Sylesti lays eggs, even if it's based off of a species that doesn't lay eggs, like the wolf.
  • Yahoo Answers is amusingly filled with many, many asks on which animals lay eggs. Expect plenty of entries on "Do monkeys lay eggs?" "Do whales lay eggs?" "Do hippos lay eggs?" and so on.

    Web Videos 
  • According to his mother, Little One of Tales From My D&D Campaign hatched from an egg (he's half-dragon). Made even weirder by the fact that she also claims to have spent the entire pregnancy in her human form, which is why Little One manifests so few visible marks of draconic heritage.

    Western Animation 
  • In one episode of Dinosaur Train, Mr. Pteranodon, Tiny, Buddy, and Cindy Cimolestes met an amphibious mammaliaform called Castorocauda. Cindy (who's a stem-placental mammal) is so shocked to see baby Castorocaudas hatch from eggs that she almost faints.
  • The Simpsons:
  • Gargoyles hatch from eggs roughly the size and shape of watermelons. According to creator Greg Weisman, the egg shells are malleable and leathery at first, but soon harden.
  • In Family Guy, Peter mentions that he thought dogs came from eggs.
  • In Justice League Unlimited, when referencing Shayera's pregnancy with his son Warhawk, Static tells Green Lantern, "Shayera was one cranky pregnant lady. Though to be fair, if I laid an egg that big..." Luckily, he was just kidding.
  • Rocko's Modern Life gives an Interspecies Romance example, when Dr. Hutchinson, a cat married to a turtle, lays an egg. Apparently justified as turtles lay eggs and not only is she married to a turtle but her father is a turtle. Even weirder though, four kids come out of it, and since Heffer was the primary "egg-sitter," one of them is a cow already wearing glasses.
  • Played with on American Dragon: Jake Long. Jake spends an entire episode protecting a griffin egg, finally returning it to its mother. It then hatches...and the mother eats the baby. While Jake is horrified, Fu Dog calmly explains that since griffins are half-bird and half-lion, the mother just needs to carry the baby the mammalian way for a bit. Oddly, we have to presume the dragons actually don't come from eggs, since Jake's dad still doesn't know what's going on. Then again, these dragons are human most of the time anyway.
  • In the My Little Pony: Friendship Is Magic episode "Luna Eclipsed", Pinkie Pie is dressed up as a chicken for Nightmare Night. At one point she get so spooked she lays an egg. A dragon egg. Somehow.
  • Futurama: Leela, a mutated human assumed to be mammalian, mentions in "Leela and the Genestalk" that she occasionally lays an egg. This same episode establishes that her mutant DNA includes some non-mammalian elements, however, such as squid tentacles.
  • In one episode of The Penguins of Madagascar, King Julien believes that he had laid an egg. Kowalski points out that's biologically impossible... unless if Julien happens to be part-platypus.
  • The Owl House: "Echoes of the Past" reveals that despite his canine-like appearance, King hatched from an egg.
  • Total Drama Revenge of the Island: The goats that live on Camp Wawanakwa lay eggs... and also have bat wings and breathe fire, as a result of all the toxic waste that Chris dumped on the island.
  • Superfriends: The Wonder Twins' pet Gleek is an alien monkey, but it is implied in the lost season segment "Invasion of the Space Dolls" that his species reproduces by laying eggs, as Jayna mentions that he was hatched when the Super Friends are celebrating his sixth birthday.

    Real Life 
  • The Duck-Billed Platypus and Echidnas are the only living mammals to lay eggs. As an ancestral trait, egg-laying was probably much more common among mammals in the past, but by stroke of luck only a few lineages have survived to present day... and particularly aberrant ones at that, which don't fully represent what the rest of the now-extinct egg-laying mammals were even like.
    • In fact, egg-laying as an ancestral mammalian trait may have existed almost exclusively among Mesozoic mammals. In which case, there would be animals superficially looking nearly identical to badgers, otters, beavers, or possums... except that they laid eggs. The otter/beaver-like Castorocauda is probably one such example.
    • And further back millions of years before there were true mammals, there were the cynodonts: early therapsids that ranged in size from rat-size to large dog-size. Evidence has been found suggesting that cynodonts possessed fur and whiskers and thus would superficially resemble a modern mammal save for semi-sprawled front legs and a lack of external ears: however, like all therapsids outside the common ancestor of placentals and marsupials, the cynodonts were egg-layers: such as the beaver-sized Kayentatherium, which laid clutches of as many as thirty-eight eggs that the parent watched over until they hatched into tiny and fully independent young. And to drive home how odd that would look, here's a reconstruction of the visually rodent-like animal and its clutch of tiny eggs.
  • Beluga caviar sounds like this trope, but it's actually eggs from a fish called the Beluga Sturgeon. The word "beluga" comes from a Russian word meaning "white", so it's not terribly surprising that it appears in the names of unrelated species.
  • It could be argued that every species that doesn't reproduce asexually do come from fertilized eggs, with most mammals incubating in the mother's womb instead of in a shell. As the outer layer of a fertilized mammalian ovum becomes a placenta rather than a shell, whether this trope genuinely applies or not depends on how you look at it.
  • Similarly, plant seeds could be considered a kind of egg. (Alton Brown invokes this trope on Good Eats when discussing what wheat germ is. He also compares an avocado to an egg, because of both its shape and its high fat content.)
  • Here's some weirdness for ya. A good portion of mammalian DNA is non-sequencing, or "junk" DNA. That doesn't mean it doesn't do anything, though. For example, some of that is very important in allowing a fertilized egg to attach itself to the uterus. Some of that comes from Endogenous Retroviruses which basically means that an ancestor was infected with a virus that incorporated itself into their genetic code and passed it on to all future generations. Putting all that together has led scientists to theorize that it was a viral infection that allowed modern fetuses to bypass the mother's immune system and necessitate live births as opposed to eggs, splitting placentals and marsupials from other mammals.
  • While human fetuses don't have eggshells surrounding them, they do have an amniotic sac, which corresponds to the clear membrane just inside an egg's shell. Usually this splits apart and peels cleanly away from the infant before the latter emerges from the birth canal, but occasionally the sac (called a "caul") will still be completely or partially wrapped around the newborn after parturition. The caul is traditionally considered good luck.


Video Example(s):


"Rhinos don't come from eggs!"

While on a safari, the family sees a baby rhino hatch from an egg.

How well does it match the trope?

5 (12 votes)

Example of:

Main / WhaleEgg

Media sources: