Dr. Mystico: That! You think I've got a clock in my head, don't you?!
So there's something off about a person in the room. Perhaps the person is a blatant Cloudcuckoolander, a pretty blatant example of The Mad Hatter or The Loonie. Perhaps the person is spouting some blatant Insane Troll Logic or some Cloudcuckoolanguage. Maybe the person has a history of being disturbingly Ax-Crazy or is just voicing how much a macabre subject appeals to them as a clear Nightmare Fetishist. Maybe the person is just a clear oddball because they voice and do things that set them apart from their peers.
Whatever the reason, the wonders of nonverbal communication make voicing one's belief that you or someone else is a complete nutjob easily possible. Just perform one gesture: Point to your own head, and twirl your fingers in a circle. Simulating as if a cuckoo clock is going off in someone's brain. The gesture is often accompanied by a two-note whistle imitating a cuckoo clock noise and the person imitating spiraling Wingding Eyes with a Maniac Tongue for added effect.
Details can vary, using different fingers when pointing at different things, but this is how you generally tell someone that you think someone in the room is a crazed loon or is going through some clear Sanity Slippage. Though generally an insulting gesture due to deeming someone as having poor mental health, it is known to have at times been used in a friendly or reassuring manner as well; communicating something to the effect of "They're a total weirdo" in an accepting tone.
Compare Batty Lip Burbling, another gesture indicating madness.
- In Asterix, Obelix's catchphrase "These Romans are crazy!" (sometimes with another group substituted in for the Romans) is often accompanied by him tapping the side of his head with his finger as a period equivalent of this gesture. On one occasion, he says, "These Britons are crazy!" while using both hands to tap the sides of his head.
- Futurama: In Issue #45, Professor Farnsworth twirls his "finglonger" (his artificially extended finger) around his head while derisively remarking on Amy's "What-if" scenario in which everybody is a Decapodian. (He finds the idea of a "tendrilonger" ridiculous.)
- Occurs in part five of the Sonic the Hedgehog/Mega Man: Worlds Unite crossover when Xander Payne teleports Dr. Wily and Dr. Eggman to Sky Patrol right in the middle of the meeting between the heroes. After a brief imprisonment, the heroes agree to let Wily and Eggman out to hear what intel they have on Sigma's plan. Xander opts to stay in the holding cell, stating that destiny doesn't need him right now. Prompting Eggman and Wily to make the cuckoo motion. Yes Xander Payne is such a wacko that the ''mad scientists'' are the ones doing this to him, go fig.
- Happens in Madagascar when the zoo protagonists are confronted at Grand Central Station by hordes of cops, Alex tries to explain the situation they're in and mentions Marty being a bit cuckoo in the head while doing the gesture.
Alex: My friend just went a little crazy. Happens to everybody. The city gets to us all. Just went a little cuckoo in the head.Marty: Hey! Don't be calling me cuckoo in the head!
- Happens in Despicable Me 2 after Gru goes on a long tirade about how he suspects that mild-mannered restaurant owner Eduardo Perez is secretly the coveted villain El Macho. Lucy does a finger twirl to voice her disagreement and quickly changes the subject.
- Pictured above from The Three Caballeros: José Carioca does this as an aside to Donald Duck, in reference to the Aracuan, after the latter interrupts him with his antics.
- The Little Mermaid: Ariel's Beginning: After Ariel and Adella accidentally disrupt the family's "walk," Andrina briefly does the finger twirl.
- Occurs in the Diary of a Wimpy Kid segment The Last Straw, Greg has to hold hands with his Uncle Joe during a church song. To make it clear that he didn't agree to that and to avoid embarrassment, Greg turns to the pew behind him and does the "cuckoo" sign while pointing at Uncle Joe.
- Near the end of Arsenic and Old Lace, Mortimer, who up to this point has been portrayed as the Only Sane Man in his family, goes berserk from stress and charges up the staircase, just like his crazy brother Teddy, who thinks he's Teddy Roosevelt. Teddy appears from his room at the top of the stairs at this point and does the crazy finger twirl, referring to Mortimer, and then goes back into his room.
- Psychonauts in the Rhombus of Ruin: When talking to Raz about Coach Oleander (for whom he used to work), Dr. Loboto describes him as having "halitosis" while twirling his finger around the side of his head (even despite the fact that he's not the right person to make such accusations).
- In The Sims 2, any Sims witness to another Sim's aspiration failure will stare at them in bewilderment and make the "cuckoo" gesture.
- Happens in Adventure Time when it comes to Jake having to hang around Susan Strong after his experience with her trying to eat the Candy People in "Susan Strong". Jake thinks Susan is actually a deranged member of the hyoo-mans, a strange race of Fish People living in the ruins of human civilization, and pleads for Finn to stay away from her and often describes her as dangerous and insane. He makes the gesture in the page image to warn Finn that Susan is just not right in the head.
- During the American Dad! episode "Black Mystery Month", Abraham Lincoln does this in response to his wife, Mary Todd Lincoln, going on one of her loony rambles (specifically that one day, a man named "Army Neilstrong" will walk on the moon).
- Done in tandem with Invisible Anatomy in the episode "Love is in the Air" of Angry Birds Toons. King Pig falls in love with a cabbage after getting hit in a head and hallucinating it as a beautiful princess pig, much to the confusion of the onlooking minion pigs. When observing King Pig's affections to the cabbage, one of the gardener pigs twirls his gardening shears around his head in a circle while saying "cuckoo".
- Happens in Freakazoid! where Freakazoid and his pals are trapped on an island owned by a Mad Scientist in "The Island of Dr. Mystico". When Dr. Mystico goes on a They Called Me Mad! speech about his deranged experiments during a forced dinner, Freakazoid makes the gesture, which Dr. Mystico catches onto and angrily reprimands him with the page quote before revealing he drugged their food.
- Happens in Futurama at the end of "Fry and the Slurm Factory" where the Professor reports the truth of Slurm's origins to the police, but when the hopelessly addicted Fry figures out that will get Slurm outlawed he tries to make the Professor look like a senile old man. Making the "crazy" gesture when the 160-year old refers to him as his uncle.
- Garfield does this in the Garfield and Friends episode "The Sludge Monster" in response to the maniacal laughter of the owner of the hotel that the trio are staying in for the night.
- Dib of all people does this to Countess von Verminstrasser in the Invader Zim episode "Lice" after growing fed up with her obsession with lice, wild statements about a Lice Queen being the cause, and brutal treatments on him and his classmates. Subverted when it turns out she was right all along.
- My Little Pony: Friendship Is Magic: Scootaloo does this in "Lesson Zero" when she silently comments aside on the rather insane Twilight.
- The Ren & Stimpy Show:
- In "Son of Stimpy", Stimpy asks his magical nose goblins if they've seen Stinky, his very first fart. The nose goblins think he's crazy for talking to farts, and one does the cuckoo gesture.
- Another example is shown in "Fire Dogs", where Ren and Stimpy (who are disguised as dalmatians) go to the fire station to be hired as fire dogs. When Stimpy almost gives them away by saying he's a cat, Ren tells the Fire Chief that Stimpy's "not quite right in the head" while doing the finger-spinning gesture to convince him to ignore the outburst.
- Happens in the Robot Chicken episode, "1987". One sketch involved Ted Turner being told about toxic dumping and how there was nothing his company could do to stop it. Turner responds that they might not have the power, but Captain Planet does... only in this setting he's fictional and Turner plans on painting himself as the superhero to take care of it personally. One of his boardroom members turns to another and does the "cuckoo cuckoo" motion.
- Happens at times in The Simpsons:
- In "Homer's Triple Bypass", Chief Wiggum did this gesture in response after a guy leaped off the building.
- In "Lisa the Drama Queen", Lisa befriends a delusional girl who sees the world as her own idealized version of it. By the end of the episode, the girl is consumed by her fantasies and walks away from Lisa, who responds by twirling her finger next to her temple and making a cuckoo sound.
- In "Tale of two Springfields", the incompetent bodyguard of The Who allows Homer and Bart to enter the band's green room and when they protest about this, the guard insults the group by snarking out "yeah, sure, I was fired by the Who" and walking out of the room doing this gesture.
- In "You only Move Twice", Bart is put into a remedial class at school and is made to do kindergarten-grade work. He points out that he's supposed to be in 4th grade and is never going to catch up with his peers at the pace the remedial class expects him to work, and does the cuckoo gesture to indicate the absurdity of the situation. His classmates then start to copy him before the teacher puts a stop to it.
- In Teenage Mutant Ninja Turtles (2003), Michelangelo does the cuckoo gesture when describing Leo's declining mental state to Master Splinter after the Turtles' last big fight with the Shredder made him into a vicious and aggressive Knight Templar.
- Total Drama: In the Revenge of the Island episode "Grand Chef Auto," Scott hints to Mike that he knows about Mike's Split Personalities (which Mike has been playing off as method acting) by twirling his finger around his ear while referencing Mike's "funny characters."
- Apparently in Germany, tapping one's forehead or temple with your index finger (which means roughly the same thing among the German Populace) is an ill-advised act and a serious insult towards whoever it is directed.
- The sign for "crazy" in ASL is made by simply pointing a finger to your ear and twirling it.
- In a self-applied variation, Turkish singer Ebru Gündeş twirled her finger next to her head seconds before she collapsed from what turned out to be a brain aneurysm. After recovering, she explained she was trying to communicate feeling drowsy.