Nausea isn't always easy to detect in another person in real life. Sometimes you can tell by how pale they look, but they might be pale for another reason (natural coloring, lack of sunlight, makeup, other unrelated sickness).
In cartoons, however, you can tell right away as the character's face turns green. This is usually followed by vomiting, either offscreen or on. Expect this to happen if a character has just been through a wild or fast ride (typically a roller coaster), eats or smells something gross, or thinks about something unappealing (sexual or otherwise). Motion sickness can also result in this, especially seasickness. Expect a long groan and maybe a Circling Birdies motif to accompany this trope.
This is somewhat based in reality, as some people's skin does turn a fairly greenish hue when they're nauseated.
- Mr. Yuk, the public-service mascot of the Pittsburgh Poison Center at the Children's Hospital of Pittsburgh, is a bright green face gagging in disgust.
- Happens to Hyatt in Excel Saga, when she feels sick before she vomits up blood and dies (as opposed to the times when she just drops dead).
- In Mind Game, Nishi's head turns blue after tasting the food prepared by Myon. Apparently, she wasn't such a good cook.
- Turns up in The Castle of Cagliostro. Lupin's face goes green for a bit after he overstuffs himself on food. Combined with Balloon Belly.
- In one Molly and Emmett story, Emmett gets this from overeating on carnival food.
Emmett: Thanks, Molly, but I think I'll wait 'til dinner.Molly: (oblivious) Don't you want one?
- Asterix: An interesting variation happens in Asterix and the Missing Scroll; the Roman Blockbustus turns green out of fear when news that the Indomitable Gauls now have the titular scroll reaches him.
- Grimsby's face turns a very unflattering shade of green right before he bends over the ship's rail in The Little Mermaid.
- Fievel's face turns green for a few moments in An American Tail, when an alcoholic politician burps in his face.
- Happens to John in Peter Pan when he smokes a Peace Pipe.
- In Return To Neverland, Tinker Bell's entire body turns green when she gets dizzy.
- Osmosis Jones, during the scene when the eponymous, lead character (who's disguised as a germ) is at the club. After drinking a rather nasty, phlegmy beverage, he has the reaction of not only his face turning green, but his head gets twisted up and stretchy as well.
- Happens to the title character in Pinocchio when he inhales an entire cigar.
- In the direct-to-video film Popeye's Voyage: The Quest for Pappy, Olive turns green from seasickness.
Popeye: Well blow me down, a green Olive.
- In The LEGO Movie, Princess Uni-Kitty's entire body turns green from seasickness.
- In A Goofy Movie, Goofy turns pale green when he and Max ride a rollercoaster at a carnival. Then, after hurling in a restroom, Max offers him some greasy carnival food and makes him go back in again.
- A rare live-action version, in the adaptation of George of the Jungle when after beating up Lyle's henchman George sniffs his own armpit and turns bright green.
- A Russian joke goes: Why are parrots green? Because all that bobbing on those tree branches makes them sick!
- In Ramona and her Mother, Beezus remarks that her little sister is "turning green" due to carsickness.
- From Frog and Toad Are Friends, when Frog is unwell:
Toad said, "Frog, you are looking quite green."
"But I always look green," said Frog. "I am a frog."
"Today you look very green even for a frog," said Toad.
- The Very Hungry Caterpillar: In the animated special, the caterpillar turns a sickly shade of green by the end of its Saturday binge.
- In The A-Team episode "Bad Time on the Border", the boat ride to Mexico is no fun for half the team as Face and B.A. spend the whole trip seasick. Hannibal tells Face that he looks green and it "brings out the color of [his] eyes."
- In the Quantum Leap episode "8 1/2 Months", Al mentions that Sam looks "a little green around the nostrils" before he throws up due to Morning Sickness from leaping into a pregnant woman.
- On the Mr. Bean episode "Mr. Bean in Room 426" Mr. Bean turns green after realizing that he has just consumed a whole plate of bad oysters.
- In Moshi Monsters, in one of the mini-games, the character I.G.G.Y. will turn green if he eats a Glump. He can be cured with apples.
- The park guests in RollerCoaster Tycoon will be green in the face whenever they are feeling nauseous.
- In Super Sized Family, when the kids get sick, their faces turn green.
- Happens in Questionable Content in this strip.
- The Order of the Stick
- Awful Hospital: Fern's entire body is constantly green. Other characters have commented on it, but Fern sees herself normally-colored. She may or may not be an asymptomatic carrier of the Parliament's manufactured disease.
- Happens to Lila in the Hey Arnold! episode "Love and Cheese" during a ride on the tilt-a-whirl.
- In Kim Possible, Ron encounters Shego who has a cold and comments that she's looking even greener than usual.
- Star Wars: The Clone Wars: Ahsoka mentions that Rotta the Hutt is so sick, "He's turning every shade of green except the one he's supposed to be!"
- Looney Tunes
- The Bugs Bunny short Falling Hare. Bugs is in a plane that's in a power dive. As he looks out the window, he puts his fingers to his mouth and turns green. Watch it here.
- Bugs' face goes green again in A Corny Concerto, after he is supposedly shot.
- In The Wacky Worm, the crow's face turns green for a few seconds, as the result of a tummy ache from eating several apples in an attempt to find the title character.
- In the Merrie Melodies take on Horton Hatches the Egg, Horton's face turns green at one point from seasickness.
- In the short Lumber Jerks, a Goofy Gopher's face became green due to noxious fumes, after siphoning gas from a furniture truck.
- In Bushy Hare, Nature Boy gets green-faced after Bugs makes him swallow a dart by blocking one end of the blowgun, sending the dart into Nature Boy's mouth.
- In Tweety's S.O.S. Sylvester has become green after winding up seasick. Later on in the short Tweety tries to distract him from eating her by making him seasick again.
- Pictured above: Happens to Henry in The Amazing Chan and the Chan Clan episode "The Mardi Gras Caper" when he and Stanley hit a Chan Plan that results in some rather crazy driving.
- This happens to all the ponies who sampled Applejack's "baked bads" in the My Little Pony: Friendship Is Magic episode "Applebuck Season".
- In the Classic Disney Short The Riveter, Donald Duck turns green when he finds out he'll be working on the top floor of a half-constructed skyscraper.
- It would often come up as a gag in the 80s' Ninja Turtle cartoon. When the turtles are disguised in public under a trenchcoat and a hat, if they are noticed people might wonder if they are ill because their faces are green.
- King of the Hill
- Bobby Hill becomes green-faced from smoking several packs of cigarettes which his dad Hank made him do as a form of punishment, after finding out his son has been smoking.
- Happens again in "Death of a Propane Salesman" during Buckley's funeral Dale thinks that there's nothing in the coffin, he peeks inside and sees his gruesome remains, he turns pale green and vomits into the coffin.
- The Simpsons:
- In one of the original The Tracey Ullman Show shorts, "The Funeral", Bart turns green and faints upon seeing Uncle Hubert's corpse in the casket.
- In episode "Homer's Night Out", Bart becomes green-faced at the sight of some repulsive-looking seafood.
- In "The Ten Per-Cent Solution", Homer's face turns green as he acts out the part of a bloated corpse.
- Quack Pack:
- In the episode "Can't Take a Yolk", Huey, Dewey and Louie's faces get green around the gills from motion sickness on an amusement park ride.
- In "The Really Mighty Ducks", an airsick pilot turns green not only in the face, but his hands as well.
- In The Magic School Bus episode "The Magic School Bus For Lunch", a shade of green appears on each of Ralphie's cheeks due to not being able to stomach (literally), being inside Arnold's digestive system.
- In the Scooby-Doo film Scooby-Doo! Music of the Vampire, as the gang is driving across a high, rickety bridge during the song 'Done With Monsters', Shaggy looks down at the water below and becomes nauseous and green as a result.
- Shaggy also becomes green around the gills after smelling some rotten leftovers near the beginning of the What's New, Scooby-Doo? episode "A Scooby-Doo Valentine".
- In the Woody Woodpecker featurette "Socko In Morocco", the eponymous woodpecker and Buzz Buzzard's faces turn green momentarily from inhaling smoke out of a hookah.
- In the Tex Avery cartoon Screwball Squirrel, Meathead the dog is looking for Screwy Squirrel on a ship, Screwy draws a picture of water and waves it out the port window. Meathead turns bright green and leans over the ship to vomit, Screwy laughs at him for only to try it on himself and get the same results.
- In the Jungle Cubs episode, "Hulla Baloo", Prince Louie's face became green as a result of a stomach ache from eating too many bananas.
- In one episode of Waynehead, this happens to Mo' Money when he gets motion sickness on an amusement park ride.
- Any time a character is about to vomit on Kaeloo. In Kaeloo's case, since she's already green, her face turns an odd shade of yellowish green.
- In the Camp Lakebottom episode "Arachnattack", McGee turns green and starts to vomit when the little baby spider sucks up a fly.
- The Loud House: In the episode "Toads and Tiaras", Lincoln turns green when he's grossed out by Lola's retainer that he has to brush for her.
- In the Little Princess episode "What's Wrong with Gilbert", the young princess is using her cat in lieu of Gilbert the teddy bear and when Puss sails in a toy boat, the fur on his face turns green.
- Happens to Jarlesburg in the Bruno the Kid episode, "North By Southwest", after eating some bad falafels.
- Wally turns thoroughly green on a roller coaster in the Butch Cassidy and the Sundance Kids episode "The Gold Caper." It's established in an earlier episode that he also gets seasick and airsick.
- In The Amazing World of Gumball episode "The Awareness", Gumball compliments Tobias on his green rainbow costume for Green Week at school, but Tobias states that he just has food poisoning and bends over to throw up.
- Spongebob Squarepants: In the episode "Plankton Retires", SpongeBob turns green while being dizzy on a ceiling fan when spying on Plankton with Mr. Krabs.