Instant Leech Just Fall in Water

Whenever a character accidentally falls into a body of fresh water, especially a stagnant one such as a swamp or pond, expect them to come up and discover a leech - or more - attached to them somewhere. This is usually followed by a side-splitting scream or shrill squeal. Often Played for Laughs, but can be used to invoke Squick in the viewer or show the harsh reality of the work's setting.

Films -- Animation
"Naveen: My family cut me off for being a (sees leech attached to his elbow) LEECH!"
 * In The Princess and The Frog, after Tiana and Naveen have both been transformed into frogs and landed in the Louisiana swamp, Naveen explains why he has no money, even though he is a prince.


 * In The Road to El Dorado, Tulio decides to save time by walking through a pond. Cut to Miguel pulling leeches off his back.

Literature

 * On The Banks of Plum Creek, book three in the Little House On the Prairie books. The local river has leeches in it that will start nomming on you if you stay in there too long. At a party she's hosting, Laura gets even with her City Mouse rival Nelly by luring her and her friends into the river. The other girls are pleasantly grossed out by the leeches, but Nelly freaks out.
 * There are leeches in the rivers that run through Nyissa, in David Eddings Belgariad. Not only are they fast, but their bite is venomous -- once a person's been bitten, they're doomed even if they are pulled out of the water before the leeches have drained them.
 * In the final novel of the Aubrey Maturin series, Blue at the Mizzen, Stephen Maturin and Christine Wood fall into brackish West African mud. Afterward, each is covered with "astonishingly numerous and avid leeches." They use salt (brought by Christine for this purpose) to remove the leeches.
 * Jurassic Park: Ed Regis ends up with leeches on him when he falls into the moat at the Tyrannosaur paddock. Before he tears them all off, the reader is treated to him remembering that the maintenance staff said that they liked damp, warm places and "liked to crawl right up your-", at which point Regis snaps out of his shock, rips the leeches off, and legs it.

Films -- Live Action

 * In Stand By Me, a brawl between two characters sends them both tumbling into a pond. Later in the same scene, the brawl comes to a screeching halt when the one character spots a leech on the neck of the other. Cue panicking, screaming, stripping off of clothes, ripping off of leeches... and Gordy finding a leech in the worst possible place. His reaction is understandable.
 * In The African Queen, Charlie gets several leeches on him when he underwater repairing the ship. The movie subverts the typical trend of just tearing them off by having him be smart enough to force them to let go with salt.
 * In The Amazing Panda Adventure, the male and female leads both end up covered in leeches after tumbling into water, leading them to start stripping off their clothes hastily. A moment passes, then they both realize the other one is getting naked too...
 * Happens to James Bond in Octopussy, among several other animal encounters. He uses a cigarette lighter to make it let go.

Tabletop Games

 * In a short story in Dragon magazine #123 illustrating the magazine's topic of swamp environmental hazards, a man hires a guide through the swamp and notes oddities about the guide from eating raw onions and rubbing them on his arms to the series of triangular scars along his arms. When he attempts to kill the guide, he finds himself suddenly weak whereupon the guide explains the ecology of leeches and how to ward them off, such as by rubbing one's skin with onions.

Video Games

 * In Metal Gear Solid 3, pretty much any time you enter water, leeches attach themselves to you. The sound of them attaching themselves to you can be hard to hear, so you might not notice until they start quickly draining your stamina. Luckily, using Snake's cigar to burn them off is easy and effective.

Western Animation
"(To Max) "I think it's time we changed your diet.""
 * In the Avatar: The Last Airbender episode "The Swamp," all the heroes fall into a swamp. As they get up, Katara comments to Sokka that he has "an elbow leech." Cue expression of disgust when Sokka discovers the enormous slimy parasite on his elbow.
 * In an episode of Sam and Max Freelance Police, Sam and Max are forced to wade through a stream in the middle of an overgrown Central Park. When Max exits, he's covered in leeches...which promptly scream in pain and jump right back off.


 * Pinky and The Brain had this. They both fall into an African river (IIRC) and when they start talking, Pinky compliments Brain on his new hat...