A character confuses an item for another, usually due to looking or sounding similar, and uses it to make food, chemical solution, etc. This tends to be an aspect of a Lethal Chef in cooking. Alternatively, this can be intentionally done by another party by switching items for the character to overlook.
- Salt and sugar
- Flour and flower
- Re:Zero: Averted in Episode 3 of the Break Time shorts, where it is mentioned that one of Reinhard's many abilities include not confusing sugar with salt when cooking.
- In one chapter of Touhou Sangetsusei the three fairies hear about "peony hotpot" and try making it, and are disappointed to discover the flowers taste quite nasty - not having realised that "peony" is a traditional Japanese culinary euphemism for boar meat.
- Ranma ˝: The first example of Akane demonstrating her Lethal Chef tendencies involved her accidentally adding vinegar instead of wine into a dish. She goes on to make many similar mistakes later.
- The Emperor's New Groove: Kronk mistakes a bottle of llama extract for deadly poison, which results in the intended victim being transformed into a llama as opposed to full-on dead.
Ymza: This isn't poison! This is extract of... LLAMA!
Kronk: You know, in my defense, your poisons all look alike. You might think about relabeling some of them.
- A plot point in the George of the Jungle movie is how Lyle has a cigarette lighter that looks like a pistol. At the end of the movie he asks one of his African guides for it (earlier he asked for it to be cleaned as long as they're working on his camera), and the guy accidentally gives him an identically-looking real gun instead.
- 9 to 5. When Violet is making coffee for her boss Mr. Hart, she accidentally adds rat poison instead of artificial sweetener. He luckily avoids drinking it and is not poisoned.
- In a MAD Magazine "Hate Book" feature, one item was "Don't you hate discovering that you've been brushing your teeth with shaving cream?" This dates back to when shaving cream often came in squeeze tubes, similar to that of toothpaste, so such an error was actually possible.
- Goblins in the Castle: Done deliberately by the goblins, who filled the sugar bowl with salt during their mischievous rampage. William only discovers this after he's spooned some into his coffee, resulting in a Spit Take.
- The Addams Family: "Lurch and His Harpsichord": After seeing that Lurch can't resign himself to losing the harpsichord to the museum, Gomez and Fester make a duplicate of the harpsichord in the basement. After they have given the new harpsichord to Lurch (without telling him it's a replacement), the movers come by for the harpsichord and end up taking the new one.
- Mimpi Metropolitan: When Alan works as Mami Bibir's assistant, Mami Bibir orders Alan to spray her face with a face mist. The thing is Mami Bibir has multiple spray bottles in her bag. When Alan takes one of them and sprays it in her face, it turns out to be pepper spray.
- One episode of Mystery Science Theater 3000 opened with Crow having melted himself into a puddle after mistaking a Thawmaster for a Thighmaster. Then Tom Servo does just the opposite, failing to thaw out a roast beef in time for dinner after mistaking a Thighmaster for a Thawmaster.
- Square One TV: One brief sketch showed two men who were working at a restaurant discussing income and profit. One of the bills they were discussing involved window repair due to a customer's demonstration of how hard the Swedish Meatballs were, to which the cook replied "How was I supposed to know that flour and plaster weren't the same thing? I mean they're both all powdery and white...!"
- One episode of Mission: Impossible has the team infiltrate a chemical plant where the villain's henchmen are mixing deadly nerve gas. The plant's store room contains two key ingredients in similar containers, differentiated only by their labels. Invoked when the IMF use peel-and-stick labels to confuse the two chemicals. This causes the mixing process to be done in the wrong order, resulting in the anarchists getting Hoist by His Own Petard.
- Through the Dragon's Eye does in the second episode. During a break on their flight to Widge, Boris sneaks a strawberry and dips it into salt instead of sugar because Pelemots can't read.
- In the Red Dwarf episode "Kryten", Lister picks up a spray can and squirts it under his arms without taking his shirt off. He then picks up his razor and another spray can, which turns out to be deodorant. After a second to process this, he lifts his shirt, and sure enough, his armpits are covered in shaving foam. Being Lister, he scoops it up and uses it anyway.
- Drake & Josh: In "The Affair", Drake and Josh believe that their father is cheating on their mother, and do everything they can to save the marriage. At one point, they decide to cook him blueberry waffles with cinnamon in them, a favorite of his, and say that their mom made them. However, Drake mixes the cinnamon up with cumin and uses the latter, unaware that his dad's allergic to it. He and Josh then rush to help their dad out as he begins choking from an allergic reaction.
- C. W. McCall: Non-lethal example in "Aurora Borealis" — McCall recalls how he and some friends were camping next to the Green River in Wyoming, and one of the guys from New York chuckles when he points out what he thinks is smog, "clear out here in the sticks". One of the others has to tell him that's not smog — it's the Milky Way, which he'd never seen before.
- Subverted in one episode of John Finnemore's Souvenir Programme, where a man claims to make his lasagne with red fruit because it's the same colour as beef ragout, and uses icing sugar instead of flour in the white sauce, because it's basically the same thing. When he describes the fluffiness of the pasta, however, it becomes apparent that he's deliberately making a Victoria sponge cake and calling it a lasagne.
- In "A Trip to the General Store" from Bear in the Big Blue House, Ojo, Tutter and Treelo decide to host a stand selling lemonade and cookies in order to make money to spend at the general store. When they tell Bear they expect to have them all sold either tomorrow or the day after, Bear agrees to buy out their entire stock, as he has things he needs from the store today. However, he can barely choke down the lemonade. He then learns from Ojo that the "secret ingredient" is salt because, after all, it looks like sugar, so surely it's the same. He takes a pass on the cookies, claiming that he'll save them for another day.
- Pokémon Mystery Dungeon: Explorers of Sky introduces "lookalike items", meant to trick the player into using them.
- Is that a healing Oran berry, or a poisonous Oren berry?
- Will the Sleep Seed help knock out your foe, or is it a Slip Seed that will make them able to walk on water?
- Will this Reviver Seed keep you going through this tough fight? or is it the devious Reviser Seed that still revives you, only for you to immediately laugh yourself unconscious?
- A backstory snippet in Undertale mentions how King Asgore got an accidental food poisoning when his children confused "cups of butter" in a pie recipe for him with "buttercups" (a mildly poisonous flower).
- Phantasy Star II has two special pieces of equipment once you get to the planet Dezoris. On one hand, there's the Magic Cap; if worn, Dezorians always lie to you or sell things for grossly inflated prices. On the other hand, there's the Mogic Cap, which causes them to tell the truth as well as sell you things for their actual price. The Magic Caps are actually still useful, since Musk Cats inside of Skure can be spoken to with them.
- A salt vs. sugar example is seen in Lemres' story in Puyo Puyo!! 20th Anniversary. Klug finds Lemres in a dizzy, lethargic state due to Compressed Abstinence of sugar, which he uses to power his magic. Klug gives him a spoonful of what he thinks is sugar, but when Lemres consumes it, they both realize is salt, which knocks Lemres cold. Klug freaks out as he realizes his mistake.
- In Densetsu no Stafy 3, this is done using a pun. Upon arriving at the door to the Old Castle, the team learns from Mama and Papa Star over a Shell Tape that a special item is needed to open it. Starly guesses that the item is a key ("kagi" in Japanese), and Starfy heads into the stage to find it, retrieving a permission fruit ("kaki") instead. Starly angrily throws the fruit at Starfy for making the mixup, but then the bust above the door eats the fruit, unlocking it, revealing that it was the correct item after all.
- Merlitz from Dan and Mab's Furry Adventures tries to convince his teammates that he has seen an actual human, but none believe him. Worse, they presume Merlitz has lost his mind, and oust him from the group. The team leader asks The Ditz for a pink slip to formalize the outplacement, whereupon she undresses, and offers her pink slip as it's the only one she has.
- Strip #130 of Phillip M Jackson's Sequential Art has Kat ask Pip to retrieve shears, so as to cut away bubblegum from Scarlet's fur. Pip brings large hedge clippers, at which Kat scolds, "Barber not gardening, you little cretin." Poor Scarlet nearly panics.
- In "Poppy's Lost Cookbook" from Butterbean's Cafe, Miss Marmalady, a notorious Lethal Chef, substitutes salt instead of sugar when making popovers, stating that "It looks like sugar, so what's the difference?"
- Looney Tunes: In "Cat-Tails for Two," the debut of Speedy Gonzales, Bennie gets a drum of petrol, thinking the word is just a funny spelling of "water", to use to douse George after being blown up.
- In the Arthur episode, "What's Cooking?", Arthur enters a cooking competition at school, hosted by famous chef Ming Tsai, with plans to make a chocolate cake. His dad insists on wanting to help, even thought it's a kids-only competition. Arthur makes a mistake by adding baking soda instead of baking powder, resulting in a batch of brownies instead of a chocolate cake. He wants to throw them out at first, but then his brownies become a huge hit with the class, and he learns that many great foods were created by accident from Ming Tsai.
- My Little Pony: Friendship Is Magic:
- In "Applebuck Season", Applejack keeps confusing ingredients, like potato chips instead of chocolate chips or fizzy soda instead of baking soda, for the cupcakes she is helping Pinkie bake due to sleep deprivation. What resulted is a town-wide food poisoning by "baked bads".
- In "It Isn't the Mane Thing About You," Pinkie Pie and Rarity ask Zecora to brew up a mess-remover potion and a special shampoo, respectively. The two liquids are the same color, and Zecora puts them into identical, unmarked bottles. Pinkie and Rarity get the bottles switched, resulting in Rarity losing most of her mane and Pinkie flooding Sugarcube Corner with soap suds.
- In The Simpsons, Season 10 "Viva Ned Flanders", when Mr. Burns' Casino is about to get demolished using bombs, one of the demolition worker overhears Bart say, "All right! Here comes the implosion" and responds to the other with "Implosion? I thought you said—" and is interrupted when the plunger goes down. This confusion results in the casino being blasted into a huge dust cloud covering part of the town.