The Forehead: Wait a minute... Something smells fishy here. I don't think you guys are villains! The Tick: Oh no, we're- We're bad! Arthur: Yeah, the worst! The Forehead: Okay, if you guys are so evil, why don't you just... Eat this kitten!
Code Geass had "If you're so evil, shoot this Britannian!" and "If you're so evil, murder the innocents!" as tests for Suzaku. Not to mention "If you're so evil, execute your childhood mentor!" He disobeyed orders on the first, then lucked out the rest of the time when someone interrupted.
In the Unknow Zanpakutou Tales arc of Bleach, Senbonzakura is distrustful of Byakuya joining the zanpakutou side of the war, so he makes him a challenge to prove his loyalty. That challenge is to murder Sode no Shirayuki, Rukia's zanpakutou, and hand the broken remains to her afterward. Of course, Senbonzakura wasn't expecting Byakuya to actually pull it off. His reaction afterward is simply priceless.
Also used in Dangaioh, when Garimoth defies Pai Thunder aka Barius, his daughter to kill Roll in front of him. Miya and Lamda intervene, though, and Pai rejects her evil father.
Early in Kurau Phantom Memory, Kurau is asked to shoot her (incognito) friend to prove she's not with him. She pulls the trigger, but surreptitiously uses her powers to make the gun misfire.
In Gunsmith Cats, bounty hunter Rally Vincent is asked to shoot a hostage with a gun with one bullet to prove she's in with the bad guys. She uses that one bullet to sever the ropes holding the hostage and shoot one of the hostage-takers in the leg. Originally, the gun wasn't loaded at all, and she's such a gun expert that she knew it from the weight and called the bad guys out on it, that's when they gave her one bullet. It helped that she was not on particularly good terms with the hostage.
Subverted in Naruto: Sasuke tells Sakura to do this by killing his teammate Karin (who had outlived her usefulness as far as he was concerned), when she claims she wants to join him. She wasn't going to do either, it was just a ploy to kill him. Before she can do either, he tries to stab her in the back, as that was just a ploy to kill her.
Inverted in Blade of the Immortal when Shira feeds Rin a dog she befriended (without her knowing) and tells her the equivalent of: "You ate the dog, you must be evil".
An early story had Nami stabbing Usopp and pushing him into the water in order to prove her loyalty to Arlong. Of course, she was only pretending to do it, and stabbed her own hand to help with the ruse.
Even before that, Zoro did a non-verbal one on her to see if Nami is truly as cold-blooded as Arlong claims by throwing himself into the pool while tied up. Nami leaps after him without hesitation.
She was also told to shoot Luffy even earlier to prove her loyalty to Buggy. Short story shorter, she failed the test that time - lucky for the next 500 chapters or so.
Hordy Jones' men force the people of Fishman Island to step on a picture of their beloved, assassinated Queen Otohime to prove their acceptance of Jones over the old monarchy. Somewhat subverted, in that Hordy Jones plans to kill those who had signed Otohime's petition even if they did go through the Fumi-e.
During the American Tour arc, Kin goes Charlie Brown from Outta Town to infiltrate an organization of evil Choujin. When the World Choujin Federation suspect 'Chanelman' of being Kin, they put out a picture of Mayumi, as part of a Fumi-e. Kinnikuman gladly stomps on the photo, to which Meat silently remarks that this sort of test is easy for Kinnikuman, who has the least respect for his father.
Later, it's revealed that the WCF has something similar as their normal entrance test - to join them, you must bring in the severed head of a heroic Choujin. Two of the applicants try to fake it and are kicked out, while one passes by bringing the head of a rival company's former champion.
Used in Maria-sama Ga Miteru (of all things). Noriko denies that a string of Buddhist prayer beads belongs to her, so the other girls counter with "Then you should have no problem if they're destroyed then." Noriko balks, which makes Shimako (who lent them to her) confess that they're hers. It's all a big act to make Shimako realize her 'secret' of belonging to a Buddhist family while attending a Catholic school is really not an issue.
Inverted in YuYu Hakusho: When Kuwabara has his cat taken hostage by another student (who was possessed), he's ordered to steal some comics (paying for them wasn't enough) because the demon possessing the student thinks this will make Kuwabara evil.
Early in the Mega Man X manga, a maverick attempts to convince X to kill a human girl to prove he's a not a "traitor" to the reploid race. X is not pleased.
In The Batman Adventures comic, Batman goes undercover in Black Mask's organization, which then captures Batgirl. As Black Mask suspects a traitor in the group, he has each member step forward and turn a wheel, filling a tank containing Batgirl 1/7 full of water. There are seven mooks being tested, including Batman.
In an early issue, Frank Castle is attempting to infiltrate a drug cartel. He is given a gun with one bullet and told to shoot a narcotics agent the cartel had captured. He is also surrounded by several heavily armed thugs just in case he decides to use the bullet on someone else.
A later Punisher story had him infiltrating a white supremacist organization, and being told to prove his loyalty by killing a Latina reporter who'd been nosing around the group's hideout (who also happened to be his current tech guy's girlfriend). The twist is that the villain of the piece employs technology that enhances the aggression and anger of those exposed to it, which causes Frank to actually do it. He doesn't respond well to the tragic - if unintentional - lapse in his moral code.
An early story featured Bats and Green Lantern attempting to infiltrate an evil group of fascists, but getting caught almost immediately. Batman is put through brainwashing while Green Lantern watches helplessly (devoid of his ring), and afterward, the final "test" to see if Batman truly has been brainwashed, is to hand him a gun and ask him to shoot Green Lantern. Which he does — but the gun isn't loaded, fortunately. As soon as the villain relaxes his guard, however, the heroes turns the tables on him and escape. Batman hadn't been brainwashed after all; he just knew that the gun wouldn't be loaded, since the villain wouldn't want to risk having Batman shoot HIM instead.
In the first Deadshot miniseries, Deadshot is infiltrating a drug cartel for the Suicide Squad; he's asked to shoot a man they claim is an undercover FBI agent—and immediately does just that, to the dismay of his field commander Rick Flag. The FBI agent assigned to the case assures Flag that they didn't have an agent inside, but Flag points out that Deadshot didn't know that and in any case wouldn't have cared.
In one issue of Ultimate Spider-Man, Shang-Chi is applying undercover for the job of the Kingpin's bodyguard. Unfortunately, he fails the 'randomly kill that guy' test.
Played with in one New Gods comic that shows the origin of Granny Goodness. She was trained alongside a dog, who she bonded with. To graduate, her trainer ordered her to kill it. Instead, she turns around and kills him. Darkseid demands an explanation, so Granny responds that the dog was more useful, since it would obey her first, but Darkseid foremost. Darkseid commands the dog to attack her, and she kills it in self-defense. Impressed, Darkseid promotes her to her current status.
During one arc of Captain Britain and MI13, part vampire superhero Spitfire is being mentally controlled by Dracula. To test if she really is under his control or working as a mole for the good guys she is ordered to kill an innocent prisoner. She does. Even though she's not actually under Dracula's mental control.
Recently reincarnated as his child self with no memory of his evil ways, Loki of The Mighty Thor keeps trying to convince the people whose help he needs to save Thor and Earth that he's still the evil manipulator who is totally on their level (and lampshades it to his companions)
Loki: "More to fear than me"! Oh Tyr, how fun this villainous talk is! (issue 625) Loki: And the Tongue will give it to us, or else I'll tear it out at its bloody root. *turns to Ikol* That's the sort of thing I'm meant to say, yes? (issue 624)
In one of Alan Moore's Future Shocks, a mild-mannered repairman who has fallen on hard times decides on a new career as a supervillain. At the villain training school, the applicants are required to demonstrate their evilness by taking candy from a baby.
Aziraphale: I once watched with my own eyes as he helped a little old lady cross the street, and he regularly rescues kittens stuck in impossible places. Practically the patron saint of trapped kittens, he is. Crowley: Well, I ate enough of them in my day, I thought it was time for something new. Adam: Kittens or old ladies? Crowley: Both, though truth be told, the kittens were tastier.
Donnie Brasco. Johnny Depp's character must prove his worth and trustworthiness to the bad guys by killing the son of an enemy mobster. The FBI instead decides to terminate the operation at the last hour and arrest the mobsters.
All of Training Day until close to the end. It's a series of If You're So Badass Eat This Kitten tests meant to show if the new guy is up to the task of being an undercover drug cop. Or so it seems. What he's actually doing is laying a trail of "reckless" decisions to steal money from a criminal and frame the new guy for his murder.
In xXx, the main character shoots a cop to get in to Anarchy 99. He uses a fake bullet that's essentially a tranquillizer and red dye, and said cop was his fellow agent. Unfortunately this influences that agent's Face-Heel Turn. And delays the girl's Heel-Face Turn.
In New Jack City, Nino Brown relates a tale from his youth: His gang initiation involved killing someone, but it couldn't be a rival gang member ("too easy"). He ends up shooting a schoolteacher on the street in broad daylight. Unfortunately for Nino, the person he relates this tale to is undercover cop Scotty, the schoolteacher's son.
In High School High, Jon Lovitz tries to infiltrate some heroin dealers. They notice that he has no needle marks on his arms, which he explains by saying that he usually takes his drugs "in the ass". They suspect his story and tell him to shoot up. He tries but doesn't know how, and ends up snapping the rubber hose in one of the thugs' face.
Nikolai in Eastern Promises is implied to have done a variety of nasty things to get where he is.
In The Negotiator, Samuel L. Jackson plays a hostage negotiator who is framed for a crime. He knows most of his precinct is corrupt and probably in on it, so he takes hostages himself in order to attract the involvement of another precinct's negotiator, who he knows to be honest. In order to keep up the charade, he seems to execute an officer who came after him. Even the audience doesn't learn until much later that the man is still alive, merely bound and gagged out of sight.
Downplayed in Batman Begins, when Henri Ducard and Ra's Al Ghul instructs Bruce Wayne to execute a criminal in order to complete his initiation into the League of Shadows (naturally, Bruce refuses). The League is not challenging him to prove that he's evil—they are asking him to prove his commitment to a cause they think is right.
Played straighter in The Dark Knight; after the Joker kills a mobster and takes over his operation, he forces the mobster's former mooks to duel each other to the death to see which of them he'll recruit into his own gang of thugs. Also a case of Deadly Graduation.
An unusual example in Traffic: Catherine Zeta-Jones' character is asked to take a hit of the cocaine she's selling to prove it's real. She refuses on the grounds that she's eight months pregnant, and walks out—the guy she's selling stops her, and takes the cocaine himself, as he thinks her refusal was quite reasonable.
In Deep Cover, Laurence Fishburne's character is a cop working undercover as a drug dealer. When it becomes necessary to take out a competing drug dealer, he actually goes ahead & kills him.
Played with when Miles is trying to prove himself to a gang. The man they want him to shoot had previously betrayed him, and was currently claiming he was a cop.
Jean: Shoot this man. Miles: No problem. [shoots him in the arm] Jean: I meant kill him! Miles: Well, you didn't say that!
Miles is actually a former jewel thief, so he's not exactly a moral person. However, Deacon was part of the heist at the start of the film and killed Miles's protege. The strange part is that Jean is told that Miles is a Mook hired to help run drugs through customs. For some reason, Jean assumes that Miles would be willing to murder someone.
In the prologue to In the Line of Fire, Frank is meeting with his forger, Mendoza, who tells him that he had Frank's partner Al followed, and discovered that he was actually with the Secret Service. Mendoza asks him to shoot Al to prove he isn't also undercover, which Frank does - but the gun is empty. Frank immediately shoots Mendoza's two accomplices and arrests Mendoza himself: He was undercover. Later, Al asks how Frank knew the gun was empty, whether he could tell by the weight of the pistol that it was unloaded. Frank says yes, but when pressed, he admits "Well...there might have been one bullet."
In Hellboy II: The Golden Army, there happens to be a monster disguised as an old lady who Hellboy and Co are trying to get info out of by pretending to be non-good monsters. However, when Hellboy finds out her diet is kittens as she moves to start eating one, Hellboy immediately blows his cover by stopping her. By knocking her out cool and across the room.
In Enter the Dragon, Han tests Roper's moral limits with a near-literal example of this by placing his own cat in a guillotine. Roper balks. It turns out the guillotine was fake.
In The Parallax View, Joe Frady (played by Warren Beatty)—a reporter investigating a political assassination—notices all the witnesses are dying. After narrowly escaping an attempt on his life, he decides to allow people to assume he's dead (so he can go undercover). He finds a clue to the shadowy conspiracy in documents from The Parallax Corporation, some of which are a psychological test. With expert assistance Frady answers all the questions the way a sociopath would, and voila he's recruited as an assassin himself. From there, things only get murkier and more frightening...
In Bourne Ultimatum, Bourne is ordered to shoot a complete stranger at the end of his training. This is less to prove his evilness than to show that he's accepted absolute obedience to orders, no matter whether the target was known to be bad, or not, or totally innocent. But mostly the principle is the same. He accepts it, because he's tortured by waterboarding when he refuses.
Related to the Child Soldiers in Real Life, Blood Diamond has this done with Solomon's son, Dia, who was brainwashed to the point of hating his father and ratting him out when he was about to be rescued from the army. The reason was then made clear later on - that Dia believed that, after what he had done, he didn't deserve to lead a normal, happy life.
In Trade, Kevin Kline's character infiltrates an auction where a 13-year-old girl is being sold as a sex slave. When he wins the auction and goes to pick her up, her captors won't allow him to leave with her until he's taken her virginity. But since they don't insist on watching, he simply has the girl break her own hymen, so that when the captors check the bedroom and see the blood on the bed, they'll assume he had sex with her.
In The Battle of Algiers, when Ali-La-Pointe first joins the Algerian resistance, he's given a gun and assigned to shoot a policeman. He tries, but the gun is empty, and he has to run away to avoid arrest; later he's told that it was a test; if he had been a spy, the French might have let him kill an Algerian, but not a cop. Of course, whether this is a test of evil or good or something else isn't a question the movie really lets you answer. Amusingly, the test goes badly because he was too committed to the cause. He was ordered to sneak up behind a policeman and shoot him in the back. Instead, he angrily confronts the policeman and pulls the trigger of an empty gun.
In Inside Man, the lead detective (Denzel Washington) believes that the bank robbers are not murderers and therefore won't go through with any hostage executions. While inside the bank to check on the hostages, he insults the lead bank robber and attacks him specifically trying to provoke him into shooting him. When he leaves, he's convinced that he's proven his point... until they shoot a hostage in retaliation for his behavior. In the end he was right. They faked the whole thing just to make him believe they would eat kittens.
In a variant from Dog Soldiers, one of the troopers washes out of training as a commando because he refused to kill the tracker dog sent to pursue him in a field operation. Not an infiltration, but a similar moral quandry that his commander berates him for shying away from.
In Queen of the Damned, when the other Ancients rejects Akasha's plans to subject the world again, she demands that Lestat kill Jesse to prove his loyalty to her. He does feed on Jesse, but fails to kill her, and then attacks Akasha.
Lampshaded in Hope And Glory where the hero proves his worthiness to join a boy's club by his knowledge of real swear words.
In the Russian WW2 film Ballada o Bombere (2011), Linko has to denounce, then shoot a fellow prisoner before he's allowed to join a collaborationist police unit. The German officer in charge says it's the first time he ever saw one of them not hesitate to kill a man for a bowl of soup (the unit gets better rations than the other Soviet POW's).
In The Lego Movie, President Business demonstrates his superweapon, the Kragle, by forcing Bad Cop to use it upon his parents. He initially refuses, thanks to his good cop side, before President Business removes his Good Cop persona (with a Q-tip and nail polish remover). He is then perfectly willing to go through with the deed.
In the Andrew VachssBatman novel The Ultimate Evil, a pedophile organization requires new members to have sex with a child before being shown any of the group's operations, in order to weed out undercover cops.
John D. MacDonald's novel The Green Ripper. Travis McGee tries to join the Church of the Apocrypha, a terrorist religious cult. As part of his Kitten Eating Test he is ordered to shoot someone.
In the Modesty Blaise novel The Night of Morningstar, a CIA agent is trying to infiltrate a terrorist organization that has a murder-the-helpless-teenage-girl type Kitten Eating Test. After some internal struggle, he goes through with it to preserve his cover — and then they tell him that they already knew he was CIA, and made him do the test anyway just to mess with him.
Jon Snow actually does eat the kitten more than once. Of course, it's getting harder and harder to tell who the kitten is. At least one of those kittens his superior officer Qorin Halfhand specifically orders Jon to do whatever is asked of him - the first thing being to kill him - so that Jon could infiltrate the wildlings. Most of the rest are Kick the Dog moments—betraying his lover, watching her die, repeatedly going against his "brothers" in the Night's Watch in a quest for personal vengeance...
In the same series, the Unsullied, at the end of their Training from Hell are required to kill a baby. At an earlier point in the training, they also had to strangle a dog they received as a puppy. It's explicitly noted that more fail the "kill your dog" test than the "kill a baby" test. (Those that fail to kill the dog are killed themselves... and then fed to the surviving dogs as an example to the surviving Unsullied.)
In Warrior Cats, Ivypaw goes undercover in the Dark Forest after finding out they're using her., only to find out that she's up to her final loyal Dark warrior test- murder Flametail. Made funny by the fact that Flametail is an actual CAT, albeit not a kitten.
Not as evil as some of these, but in First Lensman Virgil Samms is infiltrating one of Boskone's drug rings and is required to take thionite as a test.
Later in Gray Lensman, Kimball Kinnisson needs to create a cover story so he can roam seedy mining colonies unnoticed. To that end, he decides, though it disgusts him, to start drinking and taking drugs. However, he approaches this very scientifically, studying his tolerances and behaviors as he prepares himself so that he never completely loses his mental capacity (which in the Lensman universe is your best weapon). He also avoids thionite as too dangerous and instead chooses a more-common and less-dangerous drug (a chewing tobacco-like substance called bentlam) as his apparent vice. His over-the-top violent reaction when offered thionite (it's fake, but "Wild Bill" shouldn't have known that) actually helps convince them he's NOT a patrolman, since they were expecting someone under cover to try to make plausible-sounding excuses, not deck a debutante.
In a non-evil variant, an investigator in the (awful) horror novel Creepers poses as a destitute New York City tunnel-dweller. To prove his identity and grit to the head of an underground homeless enclave, he has to eat a fire-roasted rat, guts and all.
In The Chronicles of Ancient Darkness, Torak takes the place of an apprentice Soul Eater, in order to infiltrate them and save Wolf. He has to help them with a ceremony that involves killing one of each of hunting animals: A bear, a lynx, an eagle, a wolverine, a wolf, an otter, an owl and a human. The Soul Eaters are planning on Torak being the human. In the book's society, killing a hunter is seen as extremely dishonorable and evil. He's asked to kill the owl, and for Wolf's sake, he does.
In the back-story of the Sherlock Holmes novel The Valley of Fear, the narrator describes being inducted into a Molly Maguires-type gang, including going along with them on criminal activities, including one raid in which a man is killed. At the end, he is revealed to have been a Pinkerton detective who infiltrated the gang.
In one of the Able Team novels, Carl Lyons pretends he's defected to the Unomondo organization. To test him they use Carl for the assassination of a US senator. A junkie is to rob, then shoot the senator, whereupon Carl will fire a second bullet into the senator's head to ensure his death. Carl works himself up to kill the senator, only to have the junkie (who's wired up and bouncing around) jump into the line of fire and get shot instead.
In Jonathan Coe's What a Carve Up! a journalist infiltrates an arms-dealing organization looking to do an expose; he's with some of them in a bar in a Middle Eastern country where they force the waitresses to take part in a "William Tell" game. They expect him to do it too, his target being a waitress he's made friends with. He does.
Most of the plot of Shusaku Endo's novel Silence and many of his other works centers around the treading of the fumie.
That Hideous Strength, the final part of C. S. Lewis's Ransom Trilogy features, near the climax, one of the heroes, Mark Studdock, being tested to see whether he truly considers himself part of the evil anti-Christian organization N.I.C.E. How? By ordering him to deface an ancient crucifix. He finally refuses; fortunately, his interrogator is distracted by the sudden invasion of the institute by Merlin (yes, that one). He even pointed out that to rational men like themselves such a symbolic act is completely pointless. This example is interesting because Mark isn't really an undercover "hero" so much as an Everyman who's been ingratiating himself with NICE because it's been good for his career. He's nominally Christian, but regards it as more of a country club than something to actually believe in (he's actually embarrassed about the fact that his wife has recently begun taking it seriously). Also, as he's just pointed out, from a "rationalist" viewpoint the requested act is both meaningless and considerably less "evil" than some things he's already done.
Played completely straight in one of Phillip Jose Farmer's Riverworld novels—taken prisoner by a group run by a Nazi, the heroes have the Sadistic Choice of being enslaved or killing another prisoner. Surprisingly, one of the heroes actually does it. (Two ameliorating factors: the hero in question was a caveman, and Death Is Cheap in Riverworld.)
In Sharpe's Tiger, Sharpe and Lawford are infiltrating the enemy by pretending to be deserters. To prove they're truly deserters, Sharpe's ordered to fire on a captured British prisoner (the same one they are supposed to be rescuing). He does so without hesitation because he knew the gun had no powder. Although he later assures him that he still would have done it without hesitation even if the gun had been loaded.
In Iron Fist, the second Wraith Squadron novel, Face, Kell and Dia, impersonating pirates to gain the trust of Warlord Zsinj, are invited aboard the titular Star Destroyer to meet with him. In the middle of the meeting, Castin Donn, a fellow Wraith that had snuck aboard and been captured without the other Wraiths knowing anything about it, is brought into the room and Zsinj, suspecting that Castin is one of theirs, orders them to execute him as a proof of loyalty. Face tries to talk his way out of it (claiming to have a twisted moral code that does not allow him to kill anyone unless he will make money from it) and Kell prepares himself for action in case Face's bluff fails, but Dia promptly takes the blaster offered by the Warlord and explains that she has no such moral code. Face thinks this means that she has some sort of plan and prepares for a dramatic escape, only to be shocked and horrified when Dia shoots Castin in the throat. It is revealed afterward that he was probably already dead, but it is left somewhat ambiguous even to the reader and Dia was still pretty shaken up about it.
Darth Bane had this as his first test of Zannah's dedication to the dark side in the second novel of the Darth Bane Trilogy. She slowly gained the confidence of a local creature, coming to think of it almost as a pet. She then gets it to follow her back to camp, where Bane snaps its neck and tells her to throw it in the pot, it's now dinner.
In Harry Potter and the Half-Blood Prince, this gets subverted, played straight, then subverted again when it comes to the murder of Albus Dumbledore. Draco Malfoy was sent to do the deed, but "his soul was not yet so damaged" as to accomplish it, and so failed. In the end, Severus Snape ended up doing it, thus "proving his loyalty" to the Big Bad. This appears to be played straight, until the end of the 7th Book, when it was revealed that Snape had killed Dumbledore on Dumbledore's orders, since he was dying anyway.
There's a slight example of this in Deathly Hallows. Right at the beginning, Voldemort and the Death Eaters are sitting at a table with a teacher being magically restrained floating on top of it. Voldemort doesn't command anyone to kill her, since he's the one who does it, but she begs Snape to help her, and he does nothing to stop the murder, even scoffing when Voldy asks him if he remembers her. He clearly doesn't want her dead, but he can't do anything to stop it without blowing his cover. The internal struggle the character is suffering at the moment is masterfully represented in the film adaptation by actor Alan Rickman, with just a gaze.
In Wen Spencer's Bitter Waters one of the characters is captured by a cult who think they are fighting a holy war against demons. They lock him in a room with a kitten. Their rationale is that if he eats the kitten he's evil, if he starves to death he's okay. They named the kitten Schrodinger 4.
The final test to become an assassin in the Discworld, very appropriately given the nature of the business, is to travel to a certain location and kill the person you find there. The person you kill is not a real person, just a dummy, but it's to make sure you aren't squeamish about killing another person.
There is a scene in Someone Else's War where Lieutenant Panga, who has infiltrated the Lord's Resistance Army, has to "discipline" one of the child soldiers in front of a commanding officer because not doing so would look suspicious. He breaks the poor boy's ribs.
The Specialist by Gayle Rivers. Rivers is training Iraqi special forces during the first Gulf War, and notes that their commander had a technique for weeding out anyone he didn't think had what it took to be in the unit. He'd hand a gun to a candidate and invite them to fire it out the doorway, while at the same time inviting another dubious candidate to walk down the corridor and take the random chance of being shot. If either person refused to walk or fire, he was thrown out of the unit.
An article in The Onion on new regulations of the stock market mentioned requiring brokers to pass a "Kitten-and-Hammer Ethics Test".
In Captain Vorpatril's Alliance it turns out that the hired killers sent after Tej and Rish had been contracted by a Barrayaran deep cover agent to protect his op. The same agent recruited Ivan to invite Tej on a date to make sure that the assassin and Tej didn't cross paths.
In the Star Trek: The Fall novel The Crimson Shadow, a working-class Cardassian who's got mixed up with an anti-Federation group is asked to come along as muscle when they teach some "collaborators" a lesson, and realises this is at least partly a test of how far he would go for the cause. He's actually a Cardassian military officer, seconded to the Enterprise, officially on leave and working undercover for Garak. He does go along with it, since the alternative is breaking cover, although he's deeply disturbed by what he was part of.
In Christian Nation, the person in charge of the POW camp in the new theocratic America wants those who are "born again" to prove their status by stoning Sanjay without any reluctance.
In Shadow of her Sins Bloody Margo tells Alinadar to gouge out Lady Sallivera's natural eye to prove that she's sincere about wanting to come back to her crew. Instead Ali stalls long enough for her brother to line up a shot at Margo.
In an episode of the delightfully campy live action Batman, when Robin is offered a cigarette when he tries to blend in with some rough types.
This happens in the episode "Power Play" in a rare example where the hero passes the test by actually eating "the kitten", or rather, the warrior of good. He isn't turning evil again, nor is he going Knight Templar like his team assumed. He had no idea this would happen going in and refusing would mean that the Circle would kill both of them anyway. Also, the goal of this infiltration was to stop the Apocalypse.
Previously, Angel had been given a similar ultimatum by his girlfriend, Darla. She noticed that after getting his soul back, he would only prey on murderers, rapists, and other lowlifes and evildoers, so she challenged him to kill a baby. He refused and decided to run away and bring the baby to safety instead.
In an earlier episode, in order to infiltrate a group of racist 'pure' demons (who look down on humans and hybrids, like vampire and werewolves) Angel snaps Doyle's neck. However, it's revealed that Doyle, who is half demon, comes from a species that can actually survive this.
An accidental (and fairly inoffensive) version occurs in "Guise Will Be Guise" where Wesley, pretending to be Angel, is handed a glass of blood. He tries to explain he doesn't usually drink blood in front of people but his host insists that he not mind them, and he reluctantly drinks it down.
A meta example occurs in the Buffy the Vampire Slayer episode "Innocence", where Angelus commits murder before the opening credits. In the DVD Commentary, Joss Whedon says that he didn't want anyone in the audience thinking it was a fake-out.
In the one season '80s show Outlaws, the heroic time-traveling wild west outlaws with hearts of gold who are super rich from antique pocket money attempt to infiltrate an Evil Construction Company and are "invited" essentially to rape two serving girls to seal the deal. Upon their righteous refusal the Big Bad of the episode says something like "Betrayed by their own morals, here you have them, folks, the Good Guys!" (This is a bit weird because the only villainy they were attempting to impersonate was the Corporate Evil kind, and could have reasonably at least tried to fake squeamishness about violent assault.)
Walker, Texas Ranger had a version where to get in to a group, a pair of undercover cops have to go with the gang to town to commit a crime. They're able to avoid causing real trouble by having a cop stop them and pretending to kill him, which is good enough.
A great (funny) example comes from the episode "Doppelgangland": When Willow is impersonating her vampire self and is asked to "prove it" she says, "I'm a bloodsucking fiend! Look at my outfit!" Later, when challenged again, she comes up with a way to signal her friends.
Willow: Oh yeah? Could a human do this [screams her head off] Anya: Sure. Head Vampire: Yeah, I think, yeah. Anya: Humans do that. [the Scooby Gang storms in]
An earlier scene plays the trope seriously. Faith has told the Mayor that Willow is trying to hack into his computer files, so the Mayor decides that Willow must be killed. When Faith looks upset, the Mayor assures Faith that it's too early in her Face-Heel Turn to expect that of her, and says he'll send a couple of vampires to do the job instead.
Spoofed in the episode "Life Serial". Clem and his completely harmless demon buddies play poker for kittens, literally. The reason, according to to Clem? "They're delicious!"
On 24, Jack Bauer is frequently subjected to kitten-eating tests:
Season 3: To further validate his deep-cover identity in a drug cartel, Jack gets a gang tattoo and a heroin addiction. The heroin was really a bonus for Jack, who had already earned the cartel's trust by that point.
Season 3 (again): The Salazars order Jack to kill his partner, Chase (who has no idea what's going on). Jack pulls the trigger, but the gun is empty.
Another Season 3 example, Nina decides to see if Jack has gone rogue or if he's still a government agent (and plotting her death), ... by making out with him? This is the test he actually fails, he returns the kiss, but she can tell he's faking it. Which is a nice bit of Conviction by Counterfactual Clue, since all that proved is that he still (justifiably) loathed her.
Season 4: Marwan gives the test to Dina Araz, ordering her to shoot Jack. She fails and tries to shoot Marwan instead. The gun is empty. Oops. Possibly an homage to The Battle of Algiers.
In short: Jack Bauer's real superpower is that half the time, he'll eat that kitten.
In CSI: Miami, a woman working with an undercover agent ends up murdered because 1) she refuses to take her dealer's heroin (she was pregnant) and 2) her handler refused to step in when she gave him the code phrase for "I want out".
One of these tests is given (off screen) to a Federal mole in the Salvadorian mafia. We are later shown the carved up remains of the guy he was ordered to kill, showing that he "passed."
On another episode, Tina and Julian go undercover as an aspiring porn star and her boyfriend. When the director/drug dealer they were meeting with demands a blow job right there in his office, Tina manages to stall him until he implicates himself.
An episode of The Cleaner had Arnie infiltrating a biker gang. Unfortunately for him, they force him to smoke meth, his drug of choice before he got clean, to prove he's not a cop. Things... don't end well.
In season one, deep cover agent Vincent Terranova is instructed to murder a federal agent to gain mobster Sonny Steelgrave's trust. He compliantly goes to the agent's house and shoots him ... or rather, shoots the bulletproof vest Vinny covertly warned his fellow fed to don.
Vinnie has another test later in the first season when he's infiltrating a different organization. Mel Profitt gets annoyed with one of the guests on his yacht and orders Vinnie to throw her overboard. Vinnie refuses. But it works out because Mel respects Vinnie for standing up to him.
Oz. Undercover cop Desmond Mobay uses various tricks to appear to be a user, such as palming or only partially snorting the drug. Unfortunately the inmates are wise to these tricks and force him to snort several lines of cocaine while they surround him. They insist on witnessing one of his drug deals; Mobray gets round this by selling to another undercover cop, so no law is being broken. Later they tell Mobay that to join their gang he must kill someone. Mobay, who now has a serious drug habit, murders a corrupt cop who's threatened to expose him. He eventually confesses to the crime when it sinks in how far he's strayed.
Stabler faces this when he goes undercover as a suburban drug dealer. The drug syndicate he's "contracting" with to be his new suppliers tries to get him to sample some of his own product. Stabler hotly refuses, saying that his day job runs random drug tests. It works.
In another episode, Stabler, having gone undercover to gain the trust of a serial rapist, has to rape a woman that the real rapist kidnapped. Fortunately, he's able to worm his way out of it by telling the rapist that he doesn't like doing it in front of another guy, so the rapist obliges and leaves the room. Stabler then tells the victim that he's a cop, and she needs to scream convincingly. It works.
In a first season episode of Babylon 5, Sinclair is put in this situation, having infiltrated a fanatical pro-Earth group, and is asked to prove his sincerity by killing an alien (and one he met previously at that).
Done in Season 2 of A Touch Of Cloth, after Macratty begins to suspect Jack is an undercover cop. He gives him a gun and orders him to shoot Twitch. Jack duly pulls the trigger (it helps that this is the man who killed Todd Carty), but the gun isn't loaded. Convinced Jack isn't a cop, Macratty kills Twitch himself for good measure.
Also in one episode of Star Trek: Voyager, where the former Maquis crew members were forced to begin rebelling again by hypnotic suggestion, with the only one unaffected being Tuvok. He's handed a phaser and told to kill Captain Janeway. Tuvok presses the trigger and nothing happens. When Janeway asks him about this later, he answers, "They would not have given a person they were suspicious of an active weapon." Janeway finds this bit of logic to be... less than ironclad.
In an episode of Miami Vice, Detective Gina Calabrese is attempting to infiltrate a crime lord's organization by going undercover as a prostitute. The crime lord insists she has sex with him. To protect her cover, Gina agrees.
In an episode of Seinfeld, to avoid harassment by a street gang George claims to be a former member. They don't believe him so to "prove it" he has to mug somebody on the street. Jerry's parents walk by and George tries to get them to pretend he's robbing them but they dismiss him.
George: Shhh! Listen, you gotta do me a favor. Give me your wallet. I'll give it back to you later. Morty Seinfeld: How're your folks? George: Eh, they're trying to pick out a new couch - you don't want to know. [remembering watching the Van Buren Boys] Give me your wallet, or I'll spill your guts right here on the street! Morty: What did you say? George: Come on, hurry up, old man! I'm an animal! Helen: You're being very rude. Come on, Morty. George: Please, please, they're gonna hit me! [attempts to grab Helen's purse, she starts hitting George defensively, he backs off] Morty: Tell your parents we said 'Hi!'
Subverted amusingly in one episode of Veronica Mars. Veronica actually tries to do this when she thinks she has found an Animal Wrongs Group by advocating outright terroristic tactics, but it doesn't work out because the activists are the sensible, law-abiding sort who don't believe in extreme methods.
Used preemptively in an episode. Sam, in his cover as a crooked cop, pulls the bad guy of the week over, hops into his passenger seat, and snorts a pinch of white powder before introducing himself. One of the show's signature voice-overs informs the audience that snorting a crushed-up lactase tablet isn't comfortable, but goes a long way toward establishing criminal credibility.
Not just Sam, but the whole crew use this trope frequently to maintain their cover identities with the bad guys. During the course of the show, they've yelled at, threatened, punched, and even shot at each other to prove whatever various identity they were under at the moment. Michael even mentions over voice-over how much skill/training it requires to shoot and deliberately miss but make it look like you're trying to hit.
Neal: What were you going to do if I hadn't come in? Diana: Well, I'd have put this strawberry in that guy's mouth, taken him up to my room, put a gun between his ribs and told him to shut up and sit tight, or I'd arrest him for solicitation.
In the Criminal Minds episode "The Internet Is Forever" (5x22), in order to get accepted to the UnSub's online club, which provides access to live footage of him killing people, prospective members have to download child porn onto their computers.
Caprica: Daniel Graystone's order to the U-87 to shoot his dog. He wasn't testing for evil so much as total amorality (or, more accurately, he hoped to see otherwise, indicating Zoe was inside). Zoe later says that she knew the gun was unloaded. If it hadn't been, she might have instead shot Daniel Graystone himself (her father).
In 30 Rock, Jack insists that anyone he mentors be truly ambitious, not just trying to get closer to him out of love and admiration. Thus, "if you're so ambitious, cut off my pinkie."
When MacGyver tries to join a pack of terrorists as a mole, he is given a gun and asked to kill another terrorist to prove his loyalty. Being a Technical Pacifist, he doesn't, saying that he despises leaders who are so eager to lose their men. It works.
A variant occurs in an episode of Human Target: the head villain of the episode doesn't know Chance snatched the actual hitman and is now pretending to be him. Still, this otherwise plays out fairly straight: Chance, undercover, is given the order to kill a prisoner... which he does. Then, when the boss leaves the room, he improvises a defibrillator and recuscitates the guy.
While posing as a mafia hitman, Chuck has to torture Casey. Casey takes this rather well, commenting that Chuck did him a favor by ripping out a tooth that had a cavity and saving him a trip to the dentist.
While posing as an arms dealer, Morgan invokes this on himself by pulling out his cell phone and orders someone to murder a puppy.
Morgan: I told you, murder the puppy! [hangs up] It's so hard to find good henchmen these days.
Jarod on The Pretender would face this kind of challenge when he went undercover as a shady occupation like hitman or bank robber. He'd always find a way to finesse the issue until he could bring the actual criminals to justice.
On Charmed, the episode "Wrestling With Demons" is about a demonic academy whose graduation ritual is killing an innocent.
Scarecrow and Mrs. King: In one episode Lee infiltrates a group recruiting burned-out agents to do their dirty work, who lure Amanda to their base and tell him to shoot her to prove he's genuine. He seemingly goes through with it; however it turns out that he'd purposefully missed and she'd had the foresight to fling herself into the ditch and play dead (allowing her to wait until they'd left and fetch help). The scene is used to highlight the trust and unspoken communication that has developed between the pair by this point in the series.
On LOST, Benjamin Linus has to participate in the Purge perpetrated by the group later known as the Others, so as to become one of them for good (or, should we say, for evil) ; which means helping to murder the entirety of the DHARMA Initiative people with gas poison, including his own father (whom Ben kills himself inside a van in a remote area – he later brags about killing all the people in the pit but he didn't do it all alone, and he didn't even give the order, which probably came from the leader, advised by Richard Alpert).
In the fourth finale of The Mentalist, Jane is asked to bring Lisbon's dead body to Red John as proof of his change of heart and willingness to join him.
An episode literally invokes this trope when Colbert asks Kentucky representative John Yarmuth his opinion on the topic of putting kittens in woodchippers...and Yarmuth plays straight-man in advocating the use of woodchippers in reducing the kitten overpopulation problem.
Made even more hilarious by the fact that at the time, John Yarmuth himself was showing commercials (parodying some very negative advertising by the Other Team) that had such statements as "John Yarmuth goes golfing with Saddam Hussein! John Yarmuth kicks puppies! This is what happens when you get the main editor-slash-humour-columnist for the major "alternative" newspaper in Louisville running for public office.
In the Starsky & Hutch episode "The Committee", Starsky is a Fake Defector trying to infiltrate a group of murderous vigilante cops. As his initiation ritual they tell him to kill a slimy defense lawyer; Starsky just grabs the guy and runs. (He gets away with it mainly because his partner picks that moment to show up with backup.)
In the Grand Finale of Blade The Series, Blade's sidekick/Voice with an Internet Connection Shen is captured by Marcusvan Sciver. Van Sciver tells Krista to torture Shen for information, given her past as a soldier in Iraq. Krista replies that she never tortured anyone, and Marcus simply says that she must have seen torture or the results of it. Shen secretly nods her to go ahead, and Krista mouths "I'm sorry" before she starts pulling out his fingernails. When even that is not enough to make Shen talk, she pretends to break his finger, except she breaks her own finger, knowing it'll heal, and Shen makes a pained sound.
Arrow: In "Vertigo", The Mafiya boss will only introduce Oliver to the Count if he kills an underling who has displeased him. Oliver appears to strangle him, but actually just renders him unconscious and temporarily stops his heart. Oliver carries the 'corpse' outside, then tells Diggle to get him out of town and set him up in a new identity.
The X-Files: In season five episode The Pine Bluff Variant, Mulder is forced to participate in a bank robbery when undercover with a terrorist group and is ordered to kill one of the hostages. He aims his gun but hesitates until one of the other members of the group sends him away and kills the hostage himself.
In Spartacus: War Of The Damned, Julius Caesar infiltrates the rebels by pretending to be an escaped slave who wants to join them. Nemetes tests him by presenting a captured Roman woman named Fabia whom Nemetes had raped several times and orders Caesar to rape her. Instead, Caesar gives her a Mercy Kill. Nemetes is impressed, thinking he did it because he really hates the Romans.
A season 6 episode of Castle has Beckett forced to pretend to be a woman who she discovers is a hired assassin. Her "boss" requires her to prove she's the woman she's claiming to be, in the obvious way, and she appears to do just that. (Several minutes into the episode later, it's revealed that she improvised some prop blood in the victim's kitchen, then told him to play dead. Beckett is awesome.)
A Get Smart episode had Max infiltrating KAOS by pretending to go bad and getting fired from CONTROL, where they'd hire him. Once in, they give him his first assignment - to kill 99, who they'd just captured. It turns out, however, that this nest of KAOS agents was made entirely of good-guy agents from different agencies who'd infiltrated.
The Dr. Dre song "187 (Deep Cover)" opens with Snoop Dogg forcing a guy to hit off a crack pipe to prove he isn't a cop.
Dance With The Devil by Immortal Technique. In order to join a gang, as an initiation, a guy jumps way over the Moral Event Horizon. He rapes and kills his mum
In DJ Kintaro's "FREE", the Culture Police make people step on a vinyl record (vinyl being outlawed). The one who can't do it is hauled away.
One Far Side strip, in which a jungle researcher's attempt to go undercover is met with: "So, you're a gorilla, huh? Well, then you wouldn't mind eating these grubs. In fact, we wanna to see you chug 'em."
The final test to join the Chaotic Evil Ravagers is to sacrifice an innocent to Erythnul, the god of slaughter. This serves as a means of weeding out good-aligned infiltrators seeking to destroy the Ravagers from within.
One default prerequisite for a character to take up the Assassin prestige class is that they must commit a murder for no other reason than to be accepted into the class.
Tadakatsu: It matters not how many men you throw at me! I will fell them all! Shingen: And what if I threw kittens at you, Tadakatsu? Would you kill them, too?
Fallout has an example of this; to befriend some Raiders you must execute two girls they have taken as prisoners.
Splinter Cell: Double Agent. Sam Fisher is infiltrating the terrorist group John Brown's Army. He faces a Kitten Eating Test several times, including being ordered to kill three people (the helicopter pilot who helped him escape from prison, a CIA agent and his boss Colonel Lambert), and blowing up a cruise ship. The order to shoot Colonel Lambert is also Shoot Your Mate.
This is what comprises the entire mission "No Russian" in Modern Warfare 2, in which you're undercover in a group of Russian terrorists as they massacre an airport full of defenseless civilians. You're not actually required to actively participate in the civilian massacre, but eventually the riot police show up and you inevitably have to fight through them to complete the mission. Trying to kill the terrorist leader results in a Hopeless Boss Fight of sorts, where the terrorist members become invincible and start shooting at you instead. From Bad to Worse: It turns out the terrorist leader already knew your character was undercover and kills him at the end of the level. He deliberately let your character join so he could leave your body behind at the scene, thus pinning the whole incident on an American and pushing Russia to invade the U.S.. In other words, everything your character did only played right into his hands. And even then, there's an even bigger reveal towards the end of the campaign.
Also, Modern Warfare 3 reveals that a member of Makarov's inner circle defected to the Loyalists rather than participate in the mission. There's a flashback where you get to play as him after he gets shot for being a traitor, then staggers through the airport futilely trying to stop the massacre before he passes out. That's right, one of Makarov's own men wouldn't eat the kitten.
Call of Duty: Black Ops 2 puts YOU in this position. The Big Bad has captured The Lancer, and is telling you to prove your loyalty by shooting him in the head. There's a catch to this, though: the character you're playing as has killed his allies to maintain his cover, and The Lancer is one of his closest friends. You can choose to shoot the Big Bad, but it doesn't work out well for you. Notably to get the Golden Ending, you must eat the kitten.
In Sleeping Dogs, protagonist Wei Shen is quickly singled out by the Water Street Boys' ConroyWu as a possible undercover cop or rat for his not being as immediately bloodthirsty as Conroy, and because the last guy they had like that turned out to be a cop; when their leader orders an attack against a rival gang's drug warehouse and Wei amends it to at least taking the warehouse leader alive, Conroy coerces Wei to get some blood on his hands to prove that he's not a cop. Wei does go through with this, so afterwards Conroy apologizes to Wei, admitting that "you showed your true colors tonight", and fully accepts him as a member of the Water Street Boys... unaware that while Wei's handler may not like it, his superior Superintendant Pendrew doesn't mind Wei killing criminals to maintain his cover.
Slight variation in TES: Oblivion — the Dark Brotherhood actively seeks out known murderers and offers them membership.
There's another Oblivion example. At one point in the main quest, you go undercover as one of the evil cultists you've been searching for. Turns out their initiation rite is sacrificing some poor sap to their god. It's very hard to save the guy as a statue falls on him if you just ignore him. Killing him when they ask you to makes the quest a little easier as it causes the audience watching you to leave. On the other hand, if you deliberately free him, or simply hack-and-slash your way in, you can save the victim and he will reward you later.
In The Elder Scrolls V: Skyrim, the initiation to join the Dark Brotherhood involves killing one of three individuals tied-up with bags over their heads. However at least one of them is an Asshole Victim. The Dragonborn can also Take a Third Option and kill Astrid, which changes the questline to hunting down the Dark Brotherhood instead. Killing all three of them gets you compliments on your ruthlessness.
Several Daedra Lords require you to murder people in order to receive their artifacts. Boethiah plays the trope straightest, as he requires you to prove you can be treacherous by murdering someone who trusts you on his altar before he'll even speak to you.
In the first game, a Demon Door has similar requirements— he won't open unless you "perform an act of great evil in front of him..." unless you're fully evil at the time, in which case he remarks that you "wear your evil as a shroud!" and opens immediately.
Demon Door: That was wicked! Literally.
In II The entrance exam of the Temple of Shadows used to be something easy like kicking the crutches out from under a lame man. Nowadays, you have to eat five whole live baby chicksRAW with the sort-of evil guy commenting on how horrible it is.
The very effective Spire scenes in Fable II, in which you have to infiltrate the Big Bad's headquarters. You go through progressively eviler and eviler acts, starting with obeying/disobeying the Commandant, proceeding to either keep food away from or feed starving prisoners, and finally choosing to kill/not kill a fellow guard who has been quite friendly. Fortunately, taking the good choices doesn't expose you as a spy or anything, but it does cost you some of your precious, precious experience points.
Some quest lines have you undermine evil guys. Not all of them make you do really evil stuff, but a particular quest line in Zul'Drak definitely qualifies; slaughtering an entire village of trolls and subjecting their chieftains to cruel experiments. One may argue that the trolls are evil anyway but they are definitely less of a threat than the Scourge.
Death Knight starting zone. The troll evilness is a sort of interesting case because the person actually giving the quest isn't evil so much as very cruel and vindictive. Neutral Jerkass more than Neutral Evil. So you're actually doing a good thing here, not proving your credentials.
Being a Blood Elf embodies this Trope. One early meme was that a usual quest was "Kill this kitten. FOR FUN!"
There's a questline in Stranglethorn Vale that involves joining the Bloodsail Buccaneers(temporarily, you won't lose your Booty Bay reputation). To prove that you're on their side you must kill the fleet master in Booty Bay and bring them his head. Because the Fleet Master is a Tauren, a humanoid bull, you get away with handing them a cow's head wearing a pirate hat, and they're so stupid they can't tell the difference.
Arthas, after revealing he was a Death Knight publicly, ordered Thassarian to kill his own mother to prove his loyalty. So he did.
Either subverted or played absolutely dead straight, depending on your Karma Meter position. In order to gain full access to the Sith school on Korriban (and therefore the Star Map in a tomb there), you have to demonstrate yourself to be a hard-ass bastard in the true Sith style by destroying assassin droids, executing runaway students, and betraying pretty much every other student. The subversion is that while you can behave like a murderous bastard by betraying and murdering your rivals, you can also do what any good undercover Jedi would do: cheat like crazy. You can fake the deaths of the renegade students, calm the assassin droid with a conscience down, and even redeem the ghost of a Sith Lord from centuries ago and still get in. You can even get the Star Map and then lecture the leaders of the Academy about how their backstabbing ways let you accomplish it all.
In probably the best example of subversion you stumble into a Sith mentor testing some students. They suck so he ponders on a proper punishment for them: death or torture- and turns to you for an advice. You can approve violent chices OR you can tell him to simply let them go. Just because that's what you want. If you manage to push it across hard enough the Sith is impressed with your Badassitude and vehement adherence to Sith MO and indeed lets them go.
Quest for Glory II has this in the form of a test to join the Eternal Order of Fighters, by having you kill a man after defeating him in a trial by combat. If you kill him, you get a higher rank in the EOF, which has absolutely no in-game benefit; if you spare him, you get a lower rank, but the in-game Karma Meter gets points and he speaks on your behalf in the finale, which can earn your character the title of Paladin. Of course, whether you decide to or not, the man stands up alive and well after the fight is over.
You can try to complete one quest nonviolently. However, the people you're trying to get an artifact back from will want to know you're loyal to their cause, and ask you to praise Talos, the Chaotic EvilForgotten Realms god of storms. If you do, you're struck by lightning (though it doesn't necessarily kill you) and the battle begins. (The meeting takes place outside.) Unless your main character actually is a priest of Talos. Hilariously, if you're wearing the cloak that reflects lightning, the ostensibly god-sent bolt bounces back and incinerates the guy you're talking to, ending the conversation prematurely and stopping the normally ensuing fight scene.
And of course there are the Ust'Natha quests where you have to pretend to be Drow. Though, it is possible to cheat in the one quest where you actually have to kill some innocent people.
Amusingly, during the drow kitten-eating quest, the guy they send with you in order to make sure you kill them is himself an undercover follower of Ellistrae. He would probably have cheated if you weren't around, as he thinks you're "proper" drow, and you can't cheat while he's around because you think he's a "proper" drow.
In the second FreeSpace game, in order to prove your loyalty when working as a spy amongst the Neo Terran Front rebel faction, they dare you to gun down a civilian transport. If you refuse (by waiting), they brand you a traitor and a spy and try to kill you. If you accept and destroy the ship, they call you heartless but say they knew you were a spy and try to kill you. Due to a mission scripting oversight it doesn't actually matter in the end what you do here. If you destroy the civilian ship you get a severe reprimand from your superiors, are told that you're to be tried for treason, and generally implying the end of your career as a pilot. However the game still considers the mission a success and allows you to continue through the campaign as if nothing happened - possibly because of the Shivans.
The Chzo Mythos has the Order of the Blessed Agonies' Agony of the Soul, where someone must prove their loyalty to the cult of pain by killing someone they love and rely upon.
In Metal Gear Solid 3, The Boss is suspected of being a traitor due to the Cobras' deaths (and covering for a spy, as well). She is told to stab out Naked Snake's eyes. She is about to do it when she is stopped by EVA/Tanya. This is especially tense since we know That Big Boss lost an eye at some point in his life. He loses the eye soon after in a somewhat unrelated incident.
In the Evil Ending of Neverwinter Nights 2, you must prove you have no allegiance to your former party members by killing them all singlehandedly.
In 'The Shadow Odyssey' expansion pack for Everquest 2, one quest to infiltrate a group of troll pirates involves getting ordered to kill an arena full of kittens. If you choose not to do it, you can stuff them into a sack and hide them, instead. The dialog for not killing the kittens has your player telling the troll that you ate them.
In Batman: Arkham Asylum, you can overhear one of Joker's goons telling the others that Joker once ordered him to kill his sister to prove his loyalty. He says that he did it, and that he'd been looking for an excuse to do so for years anyway. Another mook one-ups him, saying that Joker made the same request of him even though he had no sister, and wouldn't leave him alone about it until finally he killed a random woman and brought her body to Joker, claiming her as his sister.
While not really a test of evilness, in 7.62 High Caliber, the first thing the rebels demand of you is to kill a captured government official. If you refuse, they will kill you (as you're heavily outnumbered and outgunned). The problem arises when you have a mission to save that same official. The solution is to find out about the conveniently delivered blanks and blood packs, and use them to stage the death of the official, thus causing both sides to like you more.
Played with in Portal. Most players will remember Test Chamber 17: the home of the famed Companion Cube. GLaDOS coaxes Chell to use the cube in various ways to get through the test, then, in typical GLaDOS fashion, springs the trope on her by indicating that in order to complete the test, she has to "euthanize" the Cube by dumping it into the incinerator. Barring Cargo Ship, most players just get it over with since the Cube isn't alive, but GLaDOS keeps on implying your "evil" nature once you finish: "You euthanized your faithful Companion Cube more quickly than any other test subject on record. Congratulations."
In Arcanum, evil-aligned characters may ally themselves with the Dark Elves late in the game. To prove your worth to them, the first quest they give you requires you to kill the entire population of Stillwater village.
If you try to join up with the Big Bad in Long Live the Queen, his first command is for you to kill your father. Depending on how you've been building your character through the game, you may or may not be able to go through with it.
After Jason steals a uniform and ID from a mercenary in order to infiltrate Hoyt's drug-smuggling and people-trafficking ring, he's told to torture one of the captives in order to gain Hoyt's favor. Jason, who's been pretty thoroughly desensitised to violence by his experiences, goes through with it, although he angsts about it afterwards, especially because the captive turned out to be his younger brother, Riley.
The final storyline mission of the game ends with Citra trying to get Jason to kill the friends he's spent the game trying to rescue in order to prove his commitment to the Rakyat's warrior philosophy.
In Shin Megami Tensei III: Nocturne if you want to side with the Yosuga (the Might Makes Right faction and the most explicitly evil of the three Reasons), you must assist in their massacres of the Manakins (who are, for the most part, defenceless) and kill the manakin leader Futomimi.
In Shin Megami Tensei IV, the Eastern Kingdom of Mikado eventually gets torn apart by the Black Samurai's Literature and its effects on the social order. So the Four Archangels decide to have the remaining loyal Samurai randomly ask the remaining Casualries to perform the E-fumi test. No points for guessing how everyone reacts.
In the Might and Magic games where you have to choose between the Light and Dark paths, some Promotion Quests on the Dark Path require doing something simply to prove you're Dark enough. For example, in VI, the Assassin quest requires killing a young noblewoman in Celeste (she's defenseless, and simply sneaking up on her while invisible will finish her in one hit) while the Villain quest requires kidnapping a young girl. (Even easier. The hardest part of both quests is simply escaping the town or city in question, but a Town Portal can do that.) Oddly enough, completing both will lower your Reputation Score even in Deja, a place allied with the Dark Path; it seems Even Evil Has Standards regarding this sort of thing.
In The Legend Of Anne Bunny, which is very loosely based on real history, Anne is told she can't join the pirates until she kills someone. She claims to have already done it, and at least one pirate believes her. Later she confesses otherwise, but they decide she's cool off to have around anyway. Heck, they elect her captain after the mutiny.
"He rides across the nation, the thoroughbred of sin. He got the application that you just sent in. It needs evaluation, so let the games begin. A heinous crime, a show of force, a murder would be nice of course..."
And more so later: "So now assassination is just the only way. There will be blood, it might be yours, so go kill someone. Signed Bad Horse."
There's a discussion between Moist and Horrible where Moist mentions someone named "Hourglass" (presumably with some kind of time-based powers) knows a kid who's going to grow up to be President, and suggests that Horrible could kill the kid. Or that he could smother an old lady.
Team SMASK (a Doctor Who macro fanfic), to test John to see if he wants to enter the league of evil characters, he is told to shag the Racnoss. He complies.
A dramatic example in Equestria Chronicles; Icarus, established as a kind and loving pony, is told to execute a prisoner in front of the entire city. On penalty of death. While his Dad looks on. He's given five minutes to prepare.
Axe Cop: In comic #137, Axe Cop and Dinosaur Soldier try to enter the villains' secret lair, which is guarded by a giant evil head. They decide to go undercover as bad guys to get in, but the head demands that they kill a good guy to prove their badness. Luckily for them, Mr. Stocker, the useless superhero with no powers, shows up... and Axe Cop, being written by a young child, isn't one for moral dilemmas. (They can always have Uni-Man bring Mr. Stocker back to life if they need him again.)
In The Order of the Stick, Belkar's test to multi-class as a barbarian is to choose from one of three other barbarians to fight. Belkar chooses to kill all three. Subverted when the recruiter informs him that the fights weren't supposed to be to the death.
The Tick is the Trope Namer, in which the eponymous hero and his sidekick are attempting to blend in with a bunch of Obviously Evil villains to pump them for information on the location of The Enemy Awards. The Forehead gets suspicious of their villain credentials and tests them with this line. The Tick fails the test immediately. As seen here.
A heroic variant comes up in Justice League Unlimited, or rather, a character's back story. Shining Knight, a knight in modern times, relates that he was tasked to raze a village to the ground by his lord King Arthur. Knowing Arthur couldn't have been so evil as to ask that, so he let them live. In return, he is rewarded for thinking rather than obeying blindly. He uses this as a metaphor for why the Shaggy Man/General Eiling is using flawed logic when he considers all super humans a threat, and only blindly obeying "duty", regardless of harmed Innocent Bystanders, mattered.
Inverted in South Park's retelling of Great Expectations. Pip wants to prove that Estella isn't evil and gives her a bunny and insists there's no way she could kill it. She does. Pip gives her another bunny and she kills that one. This continues for a while, and only stops because she gets bored. Which is lucky, because he'd just run out of bunnies.
In Samurai Jack, Jack once had to blow up a house to enter a criminal gang. He did it, but sneakily evacuated the inhabitants first. The house was inhabitted by a kindly old man and his many cute kittens and puppies. As soon as he opens the door, Jack looks despondent.
When Bart is undercover in Shelbyville, the local kids ask him to write the graffiti "Springfield sucks" to prove himself. He seems to obey at first but really paints "Springfield rules, suckers!" instead, effectively blowing his cover with style.
One that doesn't involve Bart, in "Separate Vocations" where Lisa makes a temporary Face-Heel Turn, she tries to fit in with a group of tough girls at school, but she hasn't gone quite so far that she's willing to smoke when then give her a cigarette. However, they're really impressed when she says she'll save it to smoke in class.
The girls pretend to join the side of evil. As a test, Mojo Jojo shows them a cute little plushie and then steps on it...repeatedly. The action causes Bubbles to scream (and faint) and Blossom to look on, horrified. Buttercup, on the other hand, was all too happy to join in on the plushie-stomping...
In another episode, Bubbles dresses up as Boomer to spy on the RowdyRuff Boys. Brick puts her through a series of tests, including shooting a snot rocket and eating a cockroach. (Amazingly, Bubbles managed to convince them. She even actually ate the roach (which Butch later commented that even he found disgusting). Of course, Brick and Butch weren't all that smart...)
Totally Spies! featured this as a brainwashing test. Unable to step on a randomly (and illogically) present mouse, Alex kicks the lone instructor in the face.
In Beast Machines, Jetstorm challenged Thrust to prove his loyalty to Megatron by extracting Blackarachnia's spark. Thrust almost did it, but was interrupted by Nightscream, forcing Jetstorm to do the deed himself. This becomes rather disturbing when later information is revealed.
When Dusty on G.I. Joe was sent to infiltrate COBRA as The Mole, Cobra Commander has him fight a Mook in gladiatorial combat. He's told the battle is to the death, but wriggles out of having to kill the man in cold blood by humiliating the Mook instead. He even has an answer when he's called on it:
Cobra Commander: Why did you save him? Do I detect a vestige of mercy? Dusty: We can always use extra help on K.P.
In the Season 4 episode of The Venture Bros., "Bright Lights, Dean City," Baron Underbheit thinks he needs to do something along these lines to join the Revenge Society. So he, without hesitation, snaps his manservant's neck. Turns out they just wanted him to sign some forms.
There's a literal example in Catscratch, when one of the cats is pretending to be a dog, and has to prove it by EATING A CAT.
This happens in the second Futurama movie, when Bender wants to make a deal with the robot devil to get an army of robots to attack Yivo's dimension. The Devil tells him that a deal such as that will require a very evil act from Bender - giving him his first born son! Bender does it. The Robot Devil is impressed.
In the SWAT Kats half-episode "Cry Turmoil", T-bone feigns allegiance to the eponymous villainess, Turmoil, until Razor is found running around Turmoil's airship. Turmoil is suspicious, until T-bone volunteers to show his loyalty by personally tossing Razor off the ship. Ultimately subverted when T-bone undoes Razor's shackles just before kicking him out of the airlock, allowing Razor to jetpack to safety.
The trope is parodised in its fullest in Duck Dodgers when the Cadet is made into the lord of a race of Klingon-like aliens. When the dethroned leader brings him dessert, it turns out to be... a live kitten. And this is not a deliberate test, their race really considers kittens a delicacy!
My Little Pony: Friendship Is Magic, "Dragon Quest": Spike tags along with a dragon migration, and falls in with a pack of rowdy teenage dragons. They drag Spike into helping them raid a phoenix nest, and when they manage to find an unhatched egg they dare Spike to break it to prove he's a "real dragon". The truth The bastards wanted Spike to find the egg so that they could smash it & didn't change their minds when it hatches!
Adventure Time has the episode "Web Weirdos", where Finn and Jake get caught in a spider's web along with two insects. When the spider couple comes back, Finn tries to convince the male that he's not in cahoots with the other food just trying to escape, to which the spider says "Well okay then, eat your friend here." to which Finn then pretends to eat one of the insects.
In Pixar's film The Incredibles, Syndrome basically tells Mr. Incredible, to paraphrase, "If you've actually been driven over the edge, go right ahead and crush my subordinate Mirage to death!" This calls Mr. Incredible's bluff and Mr. Incredible can't bring himself to do it...but Mirage is justifiably pissed off that Syndrome was even willing to take that chance.
Both played straight and subverted in Young Justice. Kaldur kills (not really) Artemis in line with this trope, but what really convinces his father to trust him is that he didn't take credit for something he didn't do. Unfortunately, the rest of the Light still don't think that's enough, and give an "eat this kitten" ultimatum in capturing Blue Beetle. He goes above and beyond, capturing Blue Beetle, Impulse and Beast Boy, and blowing up Mount Justice. It's still all a ruse, but it's a pretty darn convincing one.
In He-Man and the Masters of the Universe (2002), Kobra Khan had been separated from other Snake Men all his life, and was thus reluctant to feed on sentient beings, something they had no problem with. When he succeeded in freeing the others, they saw this reluctance as "soft", and some of them tried to urge him to do so when the opportunity presented itself. (He never got the courage to do it, at least not before one or more of the heroes arrived to interrupt him.)