Whale Egg

""Look, daddy, a whale egg!""

- Ralph Wiggum, The Simpsons

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.

In fiction, it's often simplified into laying eggs like a chicken, 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, 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 Improbable Species Compatibility.

Anime and Manga

 * Digimon, though 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.
 * The fifth chapter of Eastern and Little Nature Deity revolves around a giant mysterious egg. Most characters assume it's from a cat Youkai.
 * Happy, the cat in Fairy Tail hatched from an egg. Supposedly, so did his Romantic Interest Charle. Natsu thought that Happy was a dragon.
 * There were more of them.
 * Tenchi Muyo! had Ryo-Ohki hatch from an egg. That Sasami assumed was Ryoko's. Ryoko then convinced her and Ayeka that Tenchi was the father.
 * As if this weren't enough, Ryo-Ohki looks like a rabbit and turns into a spaceship.
 * And a girl. Who will grow up . But then, both Ryo-Oh-Ki and Fuku can be considered (in a really convoluted way) to be Washu's daughters. While being spaceships. Yes, it's that kind of series.

Comics

 * Skrulls are an odd reptile/mammal cross who lay eggs, but also nurse their young. 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.

Film

 * In the Super Mario Bros movie, Daisy hatches from an egg. Turns out that, despite appearances, she's the child of a dinosaur-person and the dinosaur-people are still oviparous. (And, of course, that just brings Daisy's relationship with Luigi into question.)

Folklore

 * The Easter Bunny, according to some. They're not all chocolate, you know.
 * The bunny originated as a 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.
 * In Greek mythology, Leda, the human Queen of Sparta, lays an egg (or rather two). The father, Zeus, was a swan during conception. ...Yeah.
 * The real kicker? Leda, according to most versions of the myth, had also had sex with her human husband Tyndareus on the same day, and had conceived. The children so conceived also hatched out of eggs, in the most bizarre way possible: Pollux (Zeus' son) and Castor (Tyndareus') hatched out of one egg, while Helen (yes, that Helen, and daughter of Zeus) and Clytemnestra (yes, that Clytemnestra, and daughter of Tyndareus, according to most myths) hatched out of the other.

Literature

 * 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 human.
 * Happens as a (disturbing) twist at the end of Goosebumps book Egg Monsters From Mars.
 * Subverted in Tamora Pierce's short story Nawat. The titular character's wife does not lay eggs, despite her fears.
 * 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.
 * The ending of Dr. Seuss' Horton Hatches the Egg.

Live Action Television

 * 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.
 * Mister Seahorse himself, Mork from Ork. It's a huge egg.

Tabletop Games

 * Dungeons & Dragons:
 * A sylph is an Always Female elemental 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 or other bird features, no matter how much it resembles a mammal otherwise. Griffons, hippogriffs, owlbears, and pegasi all hatch from eggs; 5th Edition retcons it with pegasi, where they give birth to live young. It's mentioned in the description for avorials, or winged elves, that there's an in-universe Urban Legend that this is true for them, but it is not.

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 creature hatches from an egg, be it lizard-bug, or snake-monkey, or what have you.
 * 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.
 * 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)
 * There are mammals that lay eggs, just not very many of them.
 * 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.
 * See: Every single Pokémon ever. Including the whales. And the plants. And the rocks. And the ghosts. 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.
 * Though, strangely enough, there is one exception. A diary entry in the Cinnabar laboratory states that "Mew gave birth." Mew is also among a subset of Pokémon that are functionally genderless and never lay eggs.
 * Though the birth may or may not have happened, as every piece of information on Mewtwo's origins are contradicted somewhere else.
 * It could also have been just a metaphor, since it is said that Mews genes were used in the creation of Mewtwo.
 * Pokémon coming from eggs is Cracked.com's #27 Science Lesson As Taught by Famous Video Games.
 * 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 disproportionate wings! (Also to fight evil Kirby clones, but that's irrelevant at the moment.)
 * 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 pigmen and ghasts.

Web Comics

 * In El Goonish Shive the Uryuom and Seyunolu (at least, first-generation) come from eggs looking like crusty meteorites. In their case, the "egg" appears to be one stage of a symbiotic organism compiling DNA samples of the parents… all, some or none of whom may be Uryuoms (producing an Uryuom, Greater Chimera and Lesser Chimera respectively), but since an egg forms before samples are introduced, it looks the same.

Western Animation

 * The Simpsons does this when the family win a trip to Africa; a baby Rhinoceros is seen breaking out of its egg. Lisa points out that rhinos don't do that. Homer points out that they obviously do, since they just saw it happen.
 * Gargoyles hatch from eggs roughly the size and shape of watermelons. According to Greg, the egg shells are malable 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, Static tells Green Lantern, "That was one big egg..." 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. Even weirder, 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...
 * Inverted in Franklin and the Green Knight where they actually show Mrs. Turtle being pregnant rather than showing Harriet (Franklin's baby sister) hatching out of an egg.
 * In My Little Pony Friendship Is Magic "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.

Real Life

 * There are a few mammals that lay eggs, even though you wouldn't expect them to, such as the Duck-Billed Platypus and the Echidna.
 * Conversely, some animals you'd expect to lay eggs instead give birth to live young, such as certain species of sharks and snakes.
 * And then there's this story from the "Not Always Right" blog...
 * Beluga caviar sounds like this, but sadly, it's actually eggs from a fish called the Beluga Sturgeon.
 * Technically every species that doesn't reproduce asexually do come from fertilized eggs. It's just in the case of most mammals that the infant is incubated in the mother's womb instead of in a shell. (Yes, plants come from eggs too! We just call them seeds.)
 * 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 lead 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 reptiles and mammals.
 * The rattlesnake is the opposite, it is a reptile that gives birth to live young.