You Have No Idea Who You're Dealing With

A common Stock Phrase often spoken to a character who, well...you know. Can be played for laughs or as a threat (especially when the "who/what" in question is really a Not-So-Harmless Villain). Someone who can easily mop the floor with the fool who's trying to pick a fight, but doesn't feel like doing so at the moment, might say this as a final warning to back off.

When done in a comedy fashion, it's often similar to the following phone conversation: "[Person A getting more angry at Person B who is disrespecting them] Person A: Do you have any idea who you are talking to?! Person B: Yes. Do you know who I am? Person A: No. Person B: Good. [hangs up]"

Can also work with three characters, usually The Villain, The Hero, and someone else who's picking a fight with the villain, not knowing who they're dealing with - while the hero does, having faced them before, and tries to warn the third character before they get themselves killed.

It can often also be said by those who intend to Screw The Rules because they have Connections, Money, Superpowers, or because They Make Them.

See also Actually, I Am Him.

Advertising

 * This lottery commercial plays it for comedy.

Anime and Manga

 * A variant serves as one of the Catch Phrases in Tengen Toppa Gurren Lagann: "Who the hell do you think I am/we are?"
 * Post-time skip in One Piece had the fake Straw Hat crew attempting to hunt down a girl who refused to drink with them and the boy who attacked them with a plant . The Fake Luffy later "captured" someone who had earlier humiliated him  . Interestingly, none of the real Straw Hats openly broadcasted the fact that they were the authentic ones and when the Fake Straw Hats found out that they had interacted with the real ones, their reactions were appropriately stunned and terrified.
 * Also the Straw Hats (minus Robin) when they first met Aokiji didn't fully understand how powerful the Marine's top people could be and how far Luffy and the others had to go before they even remotely stood a chance against one third of the Greatest Military Powers. Not long after that, the Straw Hats meet Kizaru, and then Luffy meets Akainu; those three remain the only ones who have ever made the Straw Hats seriously angry – while actually being their enemies – and gotten away with it.

Comic Books
"Team leader: You don't know who you're dealing with. Batman: Deren, Robert. Age twenty-three. Gave a kidney to his diabetic sister two years ago. Probably needs the other one. Wilson, Scott. Thirty-four. Football knee injury. Kellerman, Dana. Twenty-nine. Took shrapnel in the shoulder during the Gulf War. Still takes pain-killers for it. Goldman, Eli. Thirty-one. Allergic to penicillin. Joint wounds are slow to heal and prone to infection. Baithswaine, Gregory. Twenty-eight. Perfect medical record. So far."
 * In Gotham Knights #31, Batman tangles with an elite black-ops team:

"Man: Some of these guys are meant to be pretty good. Delta Force, I think. Micro: I don't care if they're God's own anti-son of a bitch special forces. He'll go through them like a buzzsaw."
 * During the "Season of Mists" storyline of The Sandman, the demon Azrael seriously underestimates Morpheus and gets a lecture about it from the Shaper of Dreams for his troubles.
 * In the first arc of Garth Ennis' Punisher MAX, Frank's old partner Micro is trying to disuade a trigger happy CIA spook that, if they want to take Frank alive, swarming him with Special Forces simply won't work.

Fan Works

 * A Yakuza Mook tells this to Kyon in Kyon: Big Damn Hero. Since he's time traveling to the past, he already knows exactly whom he's dealing with.

Film
"Kay: Don't "Sir" me young man, you have no idea who you're dealing with."
 * Men in Black

"Gray: You have no idea what you're dealing with here. They can alter reality, control minds. You only see what they want you to see."
 * The Deaths of Ian Stone

"Lieutenant: I think we can handle one little girl. I sent two units, they're bringing her down now. Agent Smith: No, Lieutenant, your men are already dead."
 * The Matrix

"Ya don't know what you're messin' with. You got no idea. Ya don't know what you're lookin' at When you're lookin' here. Ya don't know what you're up against, No, no way, no how. You don't know what you're messin' with, But I'm gonna tell you now!"
 * In the film version of The Musical Little Shop of Horrors, Audrey II sings in "Mean Green Mother From Outer Space":

""You obviously...do not know...who..you're...FUCKING WITH!""
 * Happens in Blade II when Blade says, before setting of the light grenade,

"Do you have any idea who you're stealing from? You and your friends are dead!"
 * The bank manager in The Dark Knight.

"Moss: If I was cuttin' deals, why wouldn't I go deal with this guy Chigurh? Wells: No no no. You don't understand. You can't make a deal with him."
 * Later it turns out that, the man he was talking to, the mob had no idea how dangerous he was.
 * Although he doesn't say the trope exactly, in No Country for Old Men Carson Wells tries to get the gist across to anyone who asks him about Anton Chigurh. He has mixed success.

"Thor: You have no idea what you're dealing with. Tony: Uh, Shakespeare in the park? "Doth mother know you weareth her drapes"?"
 * Back to The Future, part II: "Kid, I own the police."
 * Mr. and Mrs. Smith say this to each other - after they tumble to the fact that they're assassins for rival organizations.
 * "Don't make me angry. You wouldn't like me when I'm angry"
 * The Avengers - Thor breaks Loki out of the SHIELD Quinjet, hoping to make him see reason and return to Asgard. When Iron Man interrupts his "stop this take-over-the-world nonsense and come home, brother" speech, he's not happy.

Literature

 * In the first novel, after Erast Fandorin is captured by a baddie for the nth time, said bad guy proceeds to explain that the conspiracy Fandorin is targeting is much bigger than he thinks.
 * Artemis Fowl - "Stay back, human. You don't know what you're dealing with."
 * Gets even funnier in the Time Paradox
 * That Artemis. He's just incorrigible, but fans should be happy he ignored this line.
 * Discworld - In Thief of Time, Lu-Tze has this done for him by the dojo master.

Liv-Action TV
"Bruce Gellman: You have no idea who you're dealing with. Michael Westen: No, I read the article. Most of it anyway. Scary guys, drugs, guns. Did I miss something?"
 * Burn Notice - "Fight or Flight"

"D.A. Clemmons: I suggest you keep your emotions in check, Mr Kent. You obviously have no idea who you're dealing with, here. Clark Kent: Yeah, neither do you."
 * Lois and Clark: The New Adventures of Superman - "The People vs. Lois Lane"

"Bill Buchanan: You have no idea what you're dealing with, you little ass kisser!"
 * 24 - "Day 5: 2:00 a.m.-3:00 a.m."

"William Cross: You insist on keeping Andrew in the cold, you'd better learn to live in the dark. Queen Rose Benjamin: You have no idea what you're dealing with."
 * Kings - "The Sabbath Queen"

"Cordelia: You don't know who he is. Oh, boy... you're about to get your ass kicked."
 * Angel, episode 1:

"Buffy: You ever heard the expression, "biting off more than you can chew"? ...Okay, um, how about the expression "Vampire Slayer"? Vampire: What the hell are you talking about? Buffy: Wow. Never heard that one? Okay, how about, "Oh God, my leg, my leg?" (Breaks his leg) Vampire: Oh God, my leg! Ah!"
 * And a similar character moment in the Series Fauxnale of Buffy:

"Police Officer: "Now wait a minute, buddy, who the hell do you think you're talking to? Phillip Banks: Who the hell do YOU think you're talking to?!"
 * Fresh Prince Of BelAir

"All those stories you've heard about him? They're not stories, they're true! Really, you're not telling me you don't know what's coming?"
 * Crops up in Doctor Who, especially in the revival.

Video Games
""Pathetic little fool! Do you realize who you're dealing with? I am Ganondorf and soon I will rule the world!""
 * In Max Payne, when Max confronts the cop traitor B.B., the latter keeps repeating that Max "has no idea how huge this is", referring to the conspiracy that Max doesn't even know he is after at that point.
 * Team Fortress 2 - The Scout in "Meet the Scout".
 * The Legend of Zelda: Ocarina of Time: When Ganondorf meets Link for the first time.

Web Comics

 * When Miranda Deegan shows up at the climax of an early arc in Dominic Deegan, the infernomancer sent to kill her boasts that by coming out in the open, she's just signed her own death warrant. She responds that he clearly has no idea just who he's messing with, and quickly shows just why she's considered one of the world's most powerful wizards.

Web Original
"Melvin: You really have no clue what your fucking with here, do you? Joey: Uh, yeah, I'll just be getting out of the way now. Melvin: Yeah thats what I thought."
 * Yami Marick Melvin says a variant of this to Joey while his Millenium Rod turns into a lightsaber in Yu-Gi-Oh the Abridged Series.

"Melvin: The man did not know what he was fucking with."
 * And later, after killing his own abusive father in horrible fashion:

"My name's Beethoven, Motherfucker, maybe you've head of me?!"
 * Epic Rap Battles of History: Justin Bieber Vs. Beethoven.

Western Animation
"Blackarachnia: No, Bowser Boy. You have no idea what you're dealing with."
 * Beast Wars - "Optimal Situation"

""What do you MEAN you don't agree with me?! Do you know who you're DEALING WITH?!" [slams down 'the Button' and blows up Australia, laughing maniacally]"
 * In the Ren and Stimpy episode 'Stimpy's Fan Mail', Ren imagines what it would be like to be president:


 * Invoked by Adam DeCobray in G.I. Joe: Renegades to James McCullan, moments before

Real Life

 * During the early 1990s in Britain, a traffic policeman stopped a guy speeding in a Mercedes-Benz SL and before taking the ID papers asked sarcastically: "Who do you think you are, Nigel Mansell?" The driver answered calmly: "No, officer. My name is Ayrton Senna da Silva."
 * This happened at a University where the classes had hundreds of students in a lecture hall with one professor. During a major exam, one student did not put down his pencil when time was called, but instead continued to write. After collecting the other students' papers, the professor went to the one who continued to work and demanded that he put down his pencil and turn in the test. The student ignored him and finished the test, while the professor got extremely angry. He said that since the student had disobeyed him and insulted him like this, he would be given a zero on the exam. The student stood up and demanded "Do you know who I am?" The professor, not worried in the slightest, yelled back "no". The student then shoved his paper somewhere in the middle of the stack and left the room.