Crocodile Tears

Basically, fake tears.

Many actors can be relied on their facial expressions, their voices, their looks, muscle, hair, what have you. But to be able to cry on demand? That is a rare and powerful gift.

But the power to cry on demand, without sincerity, in the hands of the Manipulative Bastard? Heaven help us all.

This trope gets its name because crocodiles can and do produce tears, but not out of emotion as humans do; it's simply a way of getting rid of excess salt. 14th century travel stories had it that they cried to draw in their prey, or as a false show of guilt or grief over the prey they were eating, and the usage has carried over to human displays of false tears over the years.

This trope is not limited to just the Manipulative Bastard, however. Children "crying" to get what they want is Truth in Television (see #6 on the Cracked.com list Six Shockingly Evil Things Babies are Capable Of.).

Often a key part of a Wounded Gazelle Gambit.

Anime and Manga

 * This trope is referenced in Ouran High School Host Club - all the male hosts seem to cry at the drop of a hat, in order to create 'emotional' scenes, and Haruhi soon stumbled on the explanation - they all use eyedrops to induce tears, though Tamaki claims he doesn't - a true host can cry on command without needing such aid! (Towards the end of that episode, Haruhi accidentally pushes Tamaki into some fairly drastic action with some surprising tears - which, as it turns out, was caused by a loose contact-lens.)
 * Blue when confronted by Ho-oh in Pokémon Special.
 * There is a literal case as one of White's agency Pokemon, a Sandile, has the specific purpose for crying for any tragic movie scene.
 * In the anime, a Teddiursa pulls this by framing Chikorita and Totodile for stealing food and beating it up. Actually, said Pokemon were trying to stop it. But when Teddiursa tries this with Bulbasaur, Ash and his friends don't fall for it this time.
 * One Naruto Non-Serial Movie had a big-name actress use eyedrops to create fake tears (because she'd become such a Broken Bird that she was now an Emotionless Girl).
 * An episode of Paranoia Agent features an Internet suicide pact between two men who are shocked to discover that their third member is a little girl. When they decide to leave her behind, she tries to guilt-trip them by crying, even though there are no visible tears.
 * Kaguya from Kaguya-sama: Love Is War carried eye drops and used them to pretend she was crying. It would be in character if she carried the eye drops around specifically to use this trope.
 * Seki visibly cried in episode 18 of Tonari no Seki-kun. Shortly thereafter he wasn't crying and showed off a bottle of fake tears.

Film
"Wallace: Was that a tear? ...How do you people do it? Did you... poke yourself in the eye? Or are you thinking right now: "My dog is dead." Lori: What's the matter with you? Are you enjoying this? Wallace: Enormously. "My dog is dead." [pokes himself in the eye] "My dog is dead.""
 * Near the end of Adams Rib, the protagonists' marriage is saved when Spencer Tracy's character cries, prompting his wife (Katharine Hepburn) to become sympathetic and ignore their differences. Soon he reveals that he was crying on purpose, and makes a point of the fact that it's not just women who are capable of that kind of emotional manipulation.
 * In Catwoman, our heroine confronts the villainess in her home, who reveals her husband's dead body which just so happens to be covered in deep scratches, right before she triggers an alarm and cues crocodile tears, screaming "IT WAS CATWOMAN!"
 * Referenced in The Man Who Knew Too Little. Wallace says something that offends Lori, and she cries briefly. Wallace, who thinks everything is a play and Lori is an actress, marvels at what he thinks is the ability to cry on demand.


 * "Let's see... One, two, three, four, five, six, seven, eight, nine. So there's ten of you, and one of me. What's a poor girl to do?!"

Literature
""Look, he is crying," said the King. "That means he is sorry." "A crocodile's tears can fool you," said Big Max. "He is crying because he did not have us for dinner." "Don't remind me," said the crocodile. He cried some more."
 * Les Larmes de Crocodile/Crocodile Tears, by Andre Francois, is pretty much a bilingual gruesome warning story for kids about what happens if you believe a crocodile when it's crying. With cute little cartoon illustrations.
 * In Robert Heinlein's Lazarus Long stories, Lazarus's Opposite Gender Clones are stated to be capable of producing tears on command. Lazarus notes that he can do it too but that it isn't very useful for males.
 * One of Tom Holt's near-interchangeable protagonists (Paul Carpenter, IIRC) at one point remembers how, when left to play with a young cousin, the little rodent would at the first hint of boredom burst into tears and run out crying "Mummy, he hit me!" Since most of Tom Holt's protagonists are Butt Monkeys and/or Chew Toys, this is pretty much standard.
 * Played with in the children's book Big Max by Kin Platt, after Big Max and the King of Pooka Pooka have escaped from a literal crocodile.

"In a dramatic televised moment, [Oliver] North, his eyes moist and his voice shaking, revealed to the committee that he was a courageous patriot, after which he became so overcome by emotion that he knocked over his bottle of Revlon eye moistener."
 * In the X Wing Series, a point is made of Gara Petothel's ability to cry on cue.
 * Splinter of the Minds Eye has Luke Skywalker, in a case of Characterization Marches On - later he's a bad liar - able to not only come up with elaborate false excuses on the spot, but also to make them convincing, to the point where he can make himself cry.
 * In I, Claudius, Claudius mentions that his sister Livilla can cry on command. She uses it to manipulate Postumus into a trap.
 * Dave Barry Slept Here:


 * Evvy in Street Magic can force herself to cry what Lady Zenadia thinks are Tears Of Weakness... by remembering the look on her mother's face when said mother told the slavemaster to sell Evvy for as much as possible.
 * In Rudyard Kipling's "The Elephant's Child", the crocodile weeps Crocodile Tears to prove his identity to the title character.

Live Action TV

 * Used in one episode of CSI, by the girl who manipulated the people around in an intrigue that resulted in murder. And our heroes found out by running a chemical analysis of the tears...
 * The second episode of Dexter featured a prolific drunk driver who specialized in these. The episode was aptly titled "Crocodile".
 * Referred to by name in an episode of Fresh Prince of Bel Air. Ashley uses them to get Will to agree to participate in a scheme, but blows it when he catches her smiling reflection in a window after he says yes.
 * In Justified, when Donovan threatens to shoot Quarles for killing Brady, Quarles tears up,

Theatre

 * Referenced by Shakespeare in a couple of plays, including Othello.

Video Games

 * Pokémon: The Dark-type move Fake Tears lowers the enemy's Special Defense stat when used.
 * Tracy from I-0 can do this.
 * Dahlia Hawthorne from the Ace Attorney series. She mainly uses them to manipulate the courtroom into looking the other way when you catch her lying her ass off on the witness stand.
 * Rise in Persona 4, lampshaded by Chie.

Web Comics

 * Zola in Girl Genius does this here. She might be really crying, but considering that she managed to out-Chessmaster Lucrezia, it's highly unlikely.

Western Animation

 * Jonny does this in an episode of Ed, Edd n Eddy when he throws a party and only the Eds show up, much to Eddy's annoyance. Eddy decided to walk out, and Jonny begins crying and saying how he only wanted to have a special day for Plank. Eddy (reluctantly) decides to stay, only for Jonny to shout, "FOOLED YA!" and stop crying.
 * On The Flintstones, Wilma would sometimes resort to this to get Fred to do something for her. Once he agreed, she would immediately perk up. Betty also did this to Barney at least once.
 * The  does this in both parts of the My Little Pony Friendship Is Magic finale "A Canterlot Wedding."