Finn: I was created out of clay.
Leo: In Gammill's own image. He must be a golem.
It's a fact of life — all placental mammals have belly buttons. Therefore, not having one indicates something very strange is afoot. Whether the person was artificially created or had some other kind of non-mammalian birth, the lack of a navel provides a visual cue that they're abnormal. Those knowledgeable of human physiology may wonder just how these people developed, not having ever been attached to placentas before.
In stories involving clones, it's a common plot device used to distinguish those inferior, artificially created creatures from natural, unique human beings and may be a source of Clone Angst.
This does not include cartoon humans who lack a belly button for art style reasons, these examples require an in-universe reason a character lacks a navel upon birth.
See Also Barbie Doll Anatomy where other attributes are missing.
- Doctor Slump: An early chapter has the Robot Girl Arale worried because she lacks a navel and her classmates find that weird, so she wants one. Except her creator Senbei thinks she wants something a bit lower, which he's never seen because of Japanese censorship. Hilarity Ensues.
- Dragon Half lampshades this when Lufa asks the half dragon Mink why she has a belly button if she hatched from an egg.
- Flint the Time Detective: When Dino's and Mite's clothes get shredded in the final episodes, the protagonists finally realize they're not human because they don't have bellybuttons.
- Mermaid Melody Pichi Pichi Pitch: Inverted, as the mermaids do have navels... except, while they can be born the normal way, most are born by taking a dead or otherwise departed mermaid's pearl to a magic shell to create a new mermaid, which would mean they shouldn't have any.
- Monster Musume: Inverted by Suu. Despite being an amorphous mass of slime who was originally "birthed" by splitting from a larger slime mass, her Slime Girl form somehow possesses a navel-shaped indentation on her "stomach". This bizarre quality has some justification, as her human shape came from directly mimicking the girls in Kimihito's harem, every one of which does possess a naturally-developed navel.
- Tokimeki ★ Mononoke Jogakkou: Youkai lack bellybuttons, so Arare has to keep hers hidden to avoid being found out as a human.
- The Incal: The Protoqueen gave birth to 78 billion duplicates of Difool. The only way the Bergs can tell the difference between the original and all the "Jondiffs" is the fact that he has a bellybutton.
- Superboy (1994): Superboy, being a clone, doesn't have a navel. He'd never given this any thought until a crossover with Icon, when he saw Rocket's navel and noticed that he didn't have one.
- There is a old joke based upon how neither Adam nor Eve would have a bellybutton because Adam was created ex nihilo and Eve was shaped from his extracted rib.
Q: If you go to Heaven and look for Adam and Eve, how will you know which two people are them?
A: They're the only two without belly buttons.
- In the short story "Child's Play" by William Tenn, a rather sad-sack lawyer (from the "present day", i.e., late 1940s) accidentally receives a "Bild-A-Man" kit from the future, an educational toy — a sort of futuristic home chemistry set — that allows children to create artificial living creatures, even including duplicate human beings. The protagonist eventually winds up making a human baby, only to realize (after it's too late to do anything about it) that he forgot to give the kid a navel.
- The City and the Stars: The people of Diaspar are created as adults and naturally lack bellybuttons.
- Dream Park: In The Barsoom Project, Martin Qaterliaraq is an Inuit shaman character in the Fimbulwinter Game. His lack of a navel is an early indication that his character was crafted from molded lava by the Raven, not born.
- Glory Road: Rufo taunts Igli, a construct, over the monster's lack of a navel. "It was plain the remark about bellybuttons had cut him to the quick. He didn't have one. Only reasonable, I suppose."
- John Carter of Mars: The Martians, despite looking like odd-colored humans, are an egg-laying species, and as such lack bellybuttons.
- The Mortal Instruments: Magnus Bane, being a warlock (half human/half demon), has no bellybutton.
- Nightside: Lilith is navel-less when she arrives, probably because she's an Eldritch Abomination who made the body for convenience's sake.
- Nights at the Circus: The Winged Humanoid Sophie Fevvers claims she was hatched from an egg in an interview, and the Intrepid Reporter speculates that, if she has a navel, she's lying. It turns out she doesn't have one.
- Percy Jackson and the Olympians: Inverted with Annabeth. Despite being born from her mom's mind, she still has a navel. She actually finds people asking her if she does to be a very annoying question.
- Song of Solomon: Pilate Dead (the sister of the second Macon Dead) is said to be born without a belly button. (Her umbilical cord shriveled up and fell off, leaving smooth, hairless, scarless skin.) She crawled out of her mother's womb after she died in the throes of childbirth.
- The Omen: In the novel-only sequels Omen IV: Armageddon 2000 and Omen V: The Abomination, it's said that Damien Jr. had no navel, which is confirmed at the end of book 5. It's because he was conceived through an act of sodomy and grew within his mother's intestine rather than a proper womb.
- Terra Ignota: The mysterious Reality Warper child Bridger has no known parents and no belly button either. As far as anyone can tell, he simply sprung into existence as a fully-formed infant, which is taken as further proof he's a sign from This Universe's God. The first time he saw a belly button, he thought it was a scar.
- Charmed (1998): "Size Matters" has a demonic construct who demonstrates to Paige that he's not like ordinary people by showing her that he lacks a belly button.
- Kyle XY: The fact that Kyle has no belly button is what alerted the people who found him that he's not quite normal.
- Clone: Clone, being the first human clone, does not have a belly button.
- Mork & Mindy: After M&M got married and had sex for the first time, Mork proved he had laid an egg by showing his navel — since he's an Orkan, he doesn't have one from the natural gestation process. Other than all the times he'd shown his belly before that episode and we'd seen it.
- The Sarah Jane Adventures: Luke Smith lacks a navel, due to being created by the Bane.
- Sorry!: In the It's a Wonderful Plot episode, Timothy loses his belly button because "he was never born".
- Space: Above and Beyond: The in-vitroes lack standard bellybuttons. Instead, they have nipple-like bumps on the back of their necks from where the artificial placentas attach to them in the womb-tanks.
- The Order of the Stick: Sabine, being a demon who was never "born" in the normal sense, doesn't have a belly-button (at least in her true succubus form).
- Questionable Content: A.I.s don't have navels, as shown when some of the female A.I.s wear midriff-baring outfits.
- Tomics: Adam and Eve lack bellybuttons since they weren't born.
- Unsounded: The Bratty Halfpint Sette doesn't have a navel. Combined with her tail, lack of nipples, slow aging, and weird interactions with the Background Magic Field of the Khert, her status as human is questioned both by characters and the fandom.
- The Champions (2018): Virgil van Dijk apparently has no belly button. Dejan Lovran deduces that it's because he's a clone, which is confirmed when he stumbles upon Liverpool's laboratory. After the Virgil clones capture Dejan, his clone shows up to assure the Zenit players that he's done with the clone conspiracy theory. Malcolm takes notice that the clone doesn't have a belly button, which his teammates dismiss as Lovran being a weirdo.
- VShojo: As an A.I., Projekt Melody logically wouldn't have a navel. When asked why she appears to, she claims she drew it on to fit in.
- American Dad!: "Steve and Snot's Test Tubular Adventure" involves Steve and Snot cloning their high school's most popular girls so they can go with their clones to the prom. Stan only realizes that the girls are clones when he tells one of them to get a belly button ring and she responds that she doesn't have a belly button.
- The Powerpuff Girls: The Girls lack belly buttons, as they were scientifically created by Professor Utonium as opposed to being born naturally.
- The Simpsons: "Treehouse Of Horror XIII" involves Homer's life being invaded by an army of clones of himself. The clones, predictably enough, lack belly buttons.
- Steven Universe: The Gems, being living rocks whose bodies are projections, lack navels. This can be seen in a few episodes where Garnet changes to clothes that show her abdomen ("Beach Party" and "Garnet's Universe") or anytime Lapis Lazuli shows up. Steven has his gem in place of a navel. In a flashback, we see that one of the first things Amethyst did upon meeting Greg was pull up his shirt to look at his belly-button, suggesting some curiosity about the concept on their part. When Steven's gem is temporarily removed, the part of his abdomen where it rested still has no belly button.
- Depending on anatomical configuration, parasitic twins may lack an independent umbilical cord during gestation, relying on their intact twin's bloodstream for survival.
- The Omphalos (bellybutton) Theory was a 19th C. argument that fossils, tree rings etc., were created as is by God to give the world the appearance of age, even though it was a recent creation. The name derives from the theory that, though logically Adam and Eve shouldn't have navels, they would have been created with them, to make them identical to their descendants.