Alice and Bob meet up at a bar. Alice is dressed very provocatively and is acting rather seductively towards Bob, which Bob is obviously enjoying. Things start to heat up between the two and they exit the bar and slip out to somewhere nearby that's dark and quiet. Things start getting intimate. Alice seems Ready For Love Making, and Bob is ready to comply but suddenly things take a horrible turn for Bob. Alice's mouth gets inhumanly wide as she seizes Bob before he can run away. Bob lets out a final scream as she eats him whole and alive.
Bob has run into a Literal Maneater. She is some sort of monster (alien, demon, vampire, etc.); who (at least superficially) resembles a beautiful woman, in order to attract obliviously unlucky men and then devour them. She (and they're usually a she, though not always) is a very popular type of evil creature to appear on Monster of the Week style shows. Expect her to be Ms. Fanservice, because that's how she lures in victims; although it's not too surprising if she turns out to be a hideous shapeshifter who's only pretending to look like a beautiful human.
Sub-trope of To Serve Man, Consuming Passion, and Death by Sex. Despite the Animal Motif involved, not inherently related to the Black Widow trope, though a Literal Maneater who legally weds her victims before consuming them would be an example of both. Compare Horny Devils, who have sometimes been portrayed as seducing people before eating them.
Also see the Femme Fatale and The Vamp, who may also use their sexuality for evil purposes, but they don't eat their lovers (at least not literally). For an inversion of this trope — a female monster who preys on women rather than men — see the Lesbian Vampire.
- The unnamed female Apostle that Guts kills in the very first scene of Berserk behaves this way, luring lustful men to her so that she can transform into her true demonic form and eat them. The page pic shows her in action during the Eclipse, luring in and devouring Corkus, who is delirious after watching everyone in his crew get killed and eaten, knowing that she is most likely another demon but not being able to help himself.
- Tokyo Ghoul:
- In the very first chapter, Cute Bookworm Kaneki scores a date with the beautiful Rize Kamishiro. They spend their date going to bookstores and discussing literature, then she asks him to walk her home because of recent Ghoul Attacks in the area. He complies, and when it's time for them to part ways, the couple ends up in an embrace... and Rize sinks her teeth into his shoulder. Turns out, she is the Ghoul responsible for all the recent killings and uses her beauty to attract young men to eat. He only escapes with his life due to a cruel twist of fate.
- In the sequel, Nutcracker uses her job as an employee at a hardcore S&M club to find male victims. She arranges for a "private session" outside of work, then kills and eats them.
- Miroku from InuYasha meets a female mantis-demon who has killed and eaten a young princess and disguises herself in a human being's skin. She makes Miroku an erotic offer first, but then she shows her true form. However, as an inversion of this trope, Miroku can kill that demon.
- Judge Dredd: There's a very rare breed of Giant Spider somewhat akin to the black widow who will take on the appearance of humans to get close enough to devour them. It initially appears as a woman to seduce hapless men, but it turns out it can take on both female and male forms to lure mates.
- A Spider-Man villain, Shathra, is an giant spider-hunting wasp from another dimension. In her first appearance, she assumed a human form and appeared on a trashy talk TV program sharing details of an alleged affair between herself and Spider-Man to lure him to her in a fit of rage. Later, she would resurface in Scarlet Spider, hunting Peter's clone "brother", Kaine. She did so by assuming the form of his love interest, Annabelle. She only revealed herself post-coitus as the real Annabelle showed up, a police officer tried to arrest Kaine, Kaine's teenage sidekick ranted about the vision quest she had just gone one, and another crazed sexual partner of Kaine's attempted to kill them all with a missile launcher.
- Mermaids in Pirates of the Caribbean: On Stranger Tides are portrayed as Enthralling Sirens who seduce sailors and devour them.
- The female werewolf pack in Trick 'r Treat.
- Serleena in Men in Black II eats (offscreen ... well, on screen, but hidden by a bush) a would-be mugger/rapist in the first few minutes of the movie.
- Jennifer Check from Jennifer's Body.
- In American Gods, Bilquis the Queen of Sheba is a literal and figurative example. She acts as a prostitute to have sex with people... Who she subsequently devours with her own vagina as her form of Human Sacrifice to keep some power.
- A predator in Stanley Weinbaum's A Martian Odyssey is telepathic/hypnotic and makes its prey "see" something highly desirable to lure it within reach.
- In one episode of Grimm, the Monster of the Week is a spider Wesen, who is involuntarily compelled to periodically suck the guts out of men to maintain her youthful appearance. Interestingly, she maintains a monogamous relationship with a male member of her species, and moonlights as a serial killer, mostly to stave off her natural urge to kill her husband.
- The salt vampire from the Star Trek: The Original Series episode "The Man Trap" mostly operates this way, though there is one exception where it takes on a hunky male form to attract Lt. Uhura.
- The Outer Limits (1995): The stranded alien fugitive in "Stranded" at one point transforms himself into a hot girl to lure a teenage boy closer so he can eat him.
- Buffy the Vampire Slayer: In "Teacher's Pet", Xander is smitten by the substitute biology teacher, Ms. French, who turns out to be a giant praying mantis who needs a virgin male to fertilize her eggs before she devours him.
- In Greek Mythology, there were female monsters called Empousae that could shape shift and would take on the appearance of beautiful women in order to seduce men and then eat them alive. Luckily, it seems that a man could repel them by cursing at them.
- Many different Youkai with human-like appearances have tales to this effect, but perhaps the most prominent is the Jorogumo; this "whore spider" is a Giant Spider who shapeshifts into the form of a beautiful woman or Geisha to seduce men, only to eat them or feed them to her children.
- The Bakeneko and Nekomata, who are malevolent ghostly cats, also commonly feature in stories where they use the forms of beautiful women to attract human men for food.
- Although normally innocuous and innocent, the Kawauso (a shapeshifting otter) does have at least one story where a female used the guise of a human maiden to lure men to a pond, where she drowned and ate them after tiring of their dalliance.
- Some stories also depict the Kitsune as a shapeshifting predator, but these are comparatively rare and they are more commonly seen as tricksters, pranksters and loving spouses instead.
- Speaking of Fantastic Foxes, the Korean Gumiho is, unlike the Japanese Kitsune, traditionally depicted as a vicious man-eating fox that uses its guise of a beautiful human maiden to get men alone so it can feast on their livers or hearts. The Chinese Huli Jing is also sometimes portrayed this way, but feeds on spiritual energy rather than flesh.
- In the Shadowrun universe, the Incubus is a large octopus-like creature that has magical powers that can make it appear as a desirable person to its prey. The critter's actual form isn't changed, only how others perceive it. One runner describes an encounter with it at the docks in the middle of the night, where his partner saw a beautiful naked woman and as he approached it, it attacked him and revealed itself as an Incubus.
- Extremely common in Dungeons & Dragons and Pathfinder, where almost every Always Female One-Gender Race of monsters does this — it's honestly easier to point out aversions or subversions, such as Pathfinder's Thriae and Sirens, than to list them all. Often overlaps with Conceive and Kill.
- In Charby the Vampirate Adria has a preference for seducing men before killing and eating them, not necessarily in that order.
- Sluggy Freelance: In "On the Run", Dr. Crabtree does this once, although she's not built around doing it all the time. She's a human whose body is so suffused with experimental nanites that she can change shape and gain other people's knowledge by eating their brains. When trying to find out what Sam knows, she goes out on a date with him and soon suggests they can go outside so she can eat his brain. Being a Casanova Wannabe who's dumb as a box of rocks, he agrees, thinking it sounds kinky.
- Courage the Cowardly Dog: One of the most iconic and horrifying Monster of the Week was the Queen of the Black Puddle, a water-demon/nymph of some sort whose underwater kingdom periodically became aligned with various real-world areas through any form of water. She hypnotized her victims and left them in a sensual trance, which made it easier for her to abduct them and take them to her domain, where she would show her true demonic appearance and devour them alive. She snatches Muriel Bagge's husband Eustace and tries to eat him, before Courage (reluctantly) rescues him.
- The villain of the Gravity Falls episode "Roadside Attraction" was a Giant Spider disguised as a human woman who lures in and eats men. Oddly, rather than take a young, beautiful form, she looks like a middle-aged woman with caked-on makeup. She apparently targets older gentlemen, and her charms do work on Stan Pines.
- The Teaser for the Men in Black: The Series episode "The Inanimate Syndrome" features a gender inverted example. Agents J and K follow a young couple into a Tunnel of Love ride at an amusement park, and they have to save the young lady by killing her boyfriend (who was really a Tresfin alien disguised as a human); as he doesn't "break hearts", he eats them.
- The Simpsons episode "Bart's Friend Falls in Love" had a Show Within a Show example, where one victim in Space Mutants 7 is preyed on by a shapeshifting mutant disguised as his wife.
- The females of some species of firefly imitate the flashes of females of different species in order to lure males of that species to them. Once the male gets close enough, the female then proceeds to eat him.
- The scientific term for this is sexual cannibalism, in which the female devours the male either before or during the act of mating. So far, it has only been observed in insect and arachnid species; the redback and black widow spiders are so named for this behavior (and gave the Black Widow trope its name), though it also shows up in praying mantis species. It's also gender inverted in one species of wolf spider, where it's the male that eats the female.
- This is literally the core foundation of the dominant form of "vore" fetishism in online media; voraphillia is a sexual fetish for the consumption of living prey, and the primary form of vore fetish art consists of a beautiful woman who plays on their appearance to attract suitors, who end up being eaten involuntarily as part of the sexual act. Such cannibalistic lovemaking doesn't necessarily have to be fatal, as the common depiction involves the "prey" being Swallowed Whole without dying and it is a purely fantastical form of fetishism, but the majority of such works do result in the prey's death, usually from being digested alive.