Something comes from a drain or a faucet of some sort as an early sign that things aren't quite right or just as a form of unsuspected horror. Blood, bugs, wads of hair or even the monster itself are popular choices. Blob Monsters, in particular, really like to invade sewer systems. In some works, it can be part of a delusion a character is having during a mental breakdown.
Depending on the situation, this may also be a sign of either some kind of supernatural effect making things work like they shouldn't, something infiltrating the building through its sewage or water pipes, or simply a sign of severe uncleanliness and deteriorating hygiene.
See also Toilet Horror, where horror scenes happen in the bathroom.
Not to be confused with It Came from the Fridge, which refers to over-aged leftovers developing into new forms of life.
- Carnival Phantasm: The HibiChika Special features a skit where Shirou and Shiki decide to solve the problem of dating everyone in their harems by instead choosing to only date the main heroine of their respective visual novels, resulting in the remaining heroines going Yandere and giving Shirou and Shiki hell for not choosing them. Ciel chooses to follow around Shiki to every restaurant he goes to so that she can replace his dishes with curry, and is so persistent that he eventually starts to hallucinate that the water from his faucet is curry.
- In the Junji Ito short Groaning Drain Pipes, sisters Reina and Shinri and their cleaning-obsessed mother are at first only mildly annoyed when their drains start to clog. Reina is more concerned that her Abhorrent Admirer Kari now knows where she lives (thanks to Shinri leading him to their house so their mother could insult him). Then the drains begin to leak a foul smell, and their pipes begin to moan. Shinri becomes convinced that Kari is causing the trouble, having crawled into their pipes to stalk them. Reina tells her that's ridiculous, as their pipes aren't more than a few centimeters wide, but it turns out Shinri is right, Kari is in their pipes, having crushed his bones and deformed his skull to crawl into their drains. When Shinri forces Reina's hand into the shower drain to prove that there's nothing in there, Reina is dragged into the pipes inch by inch as a shell-shocked Shinri watches in disbelief.
- In The Blob (1988), a man trying to fix a clogged sink puts his hand down the drain and ends up getting sucked up and killed by the titular blob.
- C.H.U.D.: The drains/sewers are one of the main ways that the CHUD can get up to human level. One of the first signs that something is wrong is Laurie's clogged shower drain, and she has opened up the sewer access to her home, which results in the creatures getting through. Later on, they pour blood on her from the shower.
- Ghostbusters II: Early in the movie, reddish slime starts coming out of Dana's shower.
- In It (2017), Bev makes the mistake of looking down the bathroom sink's drain when she hears voices in it. First she's grabbed by hairy tendrils that pull her in close, before the drain blasts a torrent of blood directly into her face.
- In The Lost Boys, when one of the vampires is pushed into a bathtub full of holy water, his blood begins coming out of the pipes, including through the bathroom and kitchen sinks.
- In The Woman in Black, the Eel Marsh House's plumbing gobs up a blob of mud into the kitchen sink, foreshadowing a ghostly visitation of an Undead Child who drowned in a bog.
- In The Clone, the eponymous quasi-living organism resides in Chicago's drainage systems and initially attacks bathers through various sinks (before it grows large enough to just start killing people in the streets).
- In It, the kids can hear the cries of Pennywise's victims through the pipes. Beverly specifically hears the voices of her dead classmates from the sink, telling her that she'll be next.
- Nightmares & Dreamscapes: In the surreal short story "The Moving Finger," a man finds a human finger poking out of the drain in his bathroom sink and moving around. His sanity begins fracturing when he realizes the finger is growing longer. The story culminates in an absurd battle involving drain cleaner, electric hedge clippers, and the finger growing long enough to fight back.
- Phantoms: Before the story starts, the Ancient Enemy (a gigantic Blob Monster) invades the homes of the people of Snowfield by going through the sewer system and coming out through the drains in their bathrooms. It then kills them and either eats them or leaves their bodies as a snack for later.
- Star Wars: In The Wildlife of Star Wars, it's mentioned that a sizable population of dianogas — octopus-like, cyclopic alien animals — lives in Coruscant's sewer systems. These mostly stay where they are, but sewer backups can pull these creatures up multiple stories and cause them to emerge from people's toilets.
- Six Feet Under has blood come spurting out of the kitchen drain in a season 4 episode. It turns out the drains in the basement mortuary room are clogged, and backed up into the house during an embalming procedure.
- Clock Tower (1995): When the faucet in a bathroom found early on is examined, it will pour blood or maggots on Jennifer's hands.
- Luigi's Mansion: Water elemental ghosts, to give Luigi the Elemental Baggage to spray water, can be found in sinks, like in the first floor bathroom.
- In The Sims 4 game pack Strangerville, one of the signs that the weirdness in town is getting worse is blue and red vines growing up through the pipes of sinks and toilets, giving your Sims Tense moodlets.
- In What Remains of Edith Finch, the sea monster that eats Molly comes up the toilet.
- All Grown Up!: In "Curse of Reptar", the gang believes that they have been cursed after throwing away their old Reptar toy, with green slime coming out of the house's faucets being one of their believed signs. In actuality, their house had faulty piping, among many other mundane explanations for the odd occurrences that day.
- We Bare Bears: In "Occupy Bears", a flashback to the Bears house hunting has them at a poorly maintained apartment. When Ice Bear looks at the bathroom, a rat comes out of the showerhead.
- In February 2013, guests at the Cecil Hotel in Los Angeles reported the water in their rooms to be colored black and to have an unusual taste. Upon further inspection, it turned out that a woman's body was in one of the hotel's water tanks.