Sometimes people are so tense it doesn't take much to scare them. Cue either a smarty alec team-mate or a foe with the taste for irony simply stating "Boo". This results in the jittery character either freaking out or begin running in a panic while screaming. Usually a Comedy Trope
but appears in genuinely scary works to show how threatening the monster/villain's presence is.
Compare Cherry Tapping
which is a minor attack downing someone rather than a minor spook and Straw That Broke The Camels Back
Film - Animated
Film - Live-Action
- Used by the Lunar Ghost in the first Scooby-Doo live action movie. Naturally Scooby screams.
- The Joker Pulls this on Vicki Vale in Batman
- Undercover Brother. When Lance gets into the limousine next to James Brown he's clearly nervous. James Brown says "Boo" to him and he almost jumps out of his skin.
- In Ghost, the title character freaks someone out by writing "BOO" on his mirror.
- In The Ninth Gate, Boris Balkan does this after killing Liana in front of her coven, making them all jump.
- The Scarecrow pulls this on Judge Death in "Judgement on Gotham", a Batman/Judge Dredd crossover comics. Death was not amused...
- In Bloom County, wheelchair-bound Vietnam vet Cutter John is having tea with his girlfriend's mother. He asks if she's nervous, since some people are nervous around the handicapped. She, smiling, says no. Last panel is him saying "Boo." and her tossing her tea and shielding herself.
- In one Halloween comic strip of FoxTrot, Jason dresses up as a ghost and practices booing. The problem is that he's booing not like a ghost, but like a dissatisfied spectator.
- In Sesame Street's "News Flash" take on Little Miss Muffet, the spider appears to know this one.
- Variaton in Brawl in the Family. Dedede and Meta Knight are stuck together by a Gooey Bomb and as Dedede is sweating Meta Knight flatly says "Boom" to get a rise out of Dedede.
- Gunnerkrigg Court on page 153, when Mort tries to sneaks up on Kat and Annie sneaks up on him.
- In Punch an' Pie, Angela comes home to this when she meets Erik for the first time.
- In the Tex Avery cartoon Slap-Happy Lion, a mouse scares a lion with a flat boo. Doing it repeatedly drives the lion mad.
- Droopy, given his nack for Off Screen Teleportation has done this a few times.
- Variant in Two Stupid Dogs. The big dog will scare cats by going to up to them and giving a deadpan "Woof." The cat will then comically seize up in fear.
- In the U.S. Acres episode "I Like Having You Around", Wade tries to convince a bug that he's not afraid of him. However, the bug just says "Boo" to him in this manner, causing Wade to freak out and run in a panic.
- Raven does this to Beast Boy in an episode of Teen Titans.
- This was also exhibited in the first act of the Mr. Bogus episode "Bookstore Bogus" with a pair of ferocious worms that Bogus encounters in a book about bugs. When Bogus claims that he's not afraid of them, the worms look at each other for a few seconds before saying "boo" to Bogus in this manner, causing him to run in a panic with the worms hot on his tail.