Kel: Last time you said "we're gonna have fun" I ended butt-naked in the zoo.
Kenan: That was the first time I ever heard a giraffe giggling.
Alice and Bob decide to take a trip to the zoo with their friends Charlie and Dave. It starts off as a fairly uneventful occasion, then Dave gets his hand bitten trying to feed the monkeys (despite the incredibly obvious "Please Do Not Feed the Monkeys" sign). Then Charlie accidentally breaks a cage in the Reptile House, releasing a 25-foot anaconda, causing an Escaped Animal Rampage. While the authorities are trying to deal with that situation and people are rushing out in panic, Alice accidentally gets knocked into the bear pit, and now it's up to Bob to figure out some way to rescue her...
Hilarity In Zoos is, essentially, just that sort of situation. Whenever a group of characters goes to the zoo, it's almost a given that something is going to happen. It might be played for either comedy or drama, but inevitably, as you might expect, An Amusing Circumstance Of Some Sort Occurs. A natural way to invoke Everything's Better with Monkeys, but on the other hand, they might be Maniac Monkeys instead. May also lead to a hilarious Escaped Animal Rampage.
- Katekyō Hitman Reborn! episode 14, "First Date!? Hell's Zoo": Highlights include having to recapture all the animals after Lambo blows up all their cages, and Ryohei testing his strength "to the extreme" by fighting a bear—at a video game.
- In Heaven's Lost Property, Ikaros, at Nymph's suggestion, frees all the animals from their cages. That would be bad enough itself, but Tomoki ends up getting stripped and is believed to be the one who freed them. This gets so out of hand that Barack Obama himself finds it a global emergency.
- An episode of Sgt. Frog had Keroro sneaking into a zoo after-hours with a ray-gun that turns animals into humans, with the hopes of recruiting some of the transformed animals as soldiers for his invasion.
- In Oumagadoki Doubutsuen, Aoi Hana gets a job in a zoo. Turns out the director is cursed, can turn any animal into Petting Zoo People and really wants to party all day.
- Yotsuba&!: Yotsuba punches a goat, freaks out on meeting an owl, and is mesmerized by the elephant.
- Two examples from The Punisher:
- The first from "Welcome Back, Frank", where Ma Gnucci and her Mooks pursued Frank into a zoo, and he, without much in the way of weapons, used the animals to fend them off (like holding a guy's head under a piranha tank), culminating in a darkly hilarious fate for Ma Gnucci herself.
- The second time is when a mook that Frank needs for information tells him about how the made man he was working for antagonized a monkey in a zoo. Said monkey proceeded to rip the guy's junk off and tossed it away, where it eventually got eaten by a vulture.
- There is a cycle of stories in the Discworld continuum concerning the establishment of a City Zoo in Ankh-Morpork. The genesis of the idea lies in C.M.O.T. Dibbler's half-baked scheme to set up a safari park in return for lots of money.
"And you thought you'd set up a... safari park. On currently vacant land outside the city where you have an option to develop. This is a new concept, mr Dibbler. Let me see if I have it correctly. You would have a large area surrounded by secure safety fences. Within which, the general public would pay to enter, and drive their carriages through, in order to safely witness exotic animals in what would be, as near as could be arranged, their natural habitat.""That's broadly it, sir, yes" said Dibbler, looking relieved."The wildlife including lions. And baboons, which are a large predatory ape. And rhinoceri. And people would then drive carriages, possibly open-topped ones, through this park to see the animals at close quarters. Carriages drawn by horses. And you see no little... problems... with this picture?""The idea can always be fine-tuned, sir. In the light of experience""Indeed, mr Dibbler. Indeed."
- The recovered animals then become the nucleus of the Ankh-Morpork City Zoo. This is under the management of a professional. Who then realises she has to train a bunch of motley amateurs to become zookeepers. Very, very, quickly.
- Anchorman: The Legend of Ron Burgundy has the scene where the Channel 4 News Team goes to the San Diego Zoo to investigate Yet Another Baby Panda. Highlights include Ron jumping into the Bear Pit to save Veronica from certain danger (without thinking his plan all the way through) and a rival news anchor getting his (one remaining) arm ripped off.
- Fierce Creatures takes place almost entirely at a zoo, so naturally they take advantage of it.
- Old Dogs: Three of the protagonists try to sneak into a zoo and end up tangling with a gorilla and killer penguins.
- Baby's Day Out : The whole sequence where the three bad guys try to retrieve the titular baby from a gorilla in a zoo. Hilarity Ensues as they get pwned by the gorilla in each of their attempts.
- In BrainDead, the zombie plague starts with a woman getting bitten by the Sumatran Rat Monkey in a zoo.
- In Osmosis Jones, Frank gets infected by Thrax when he drops a hard-boiled egg from his lunch next to the chimpanzee cage, and ends up wrestling with the one that grabbed it to reclaim and eat his now-contaminated snack.
- We Bought a Zoo is a comedy-drama that takes place almost entirely in a zoo.
- Fantastic Beasts and Where to Find Them has a scene where a female erumpent (a giant rhino-like monster with an explosive horn) breaks into Central Park Zoo, looking for a mate. She causes an Escaped Animal Rampage, setting several zoo animals free.
- In The Powerpuff Girls Movie, Mojo Jojo takes the girls to the zoo where he has the girls strategically posed for pictures in front of monkey cages so he can fire special probes into their fur for his later plan to rule Townsville.
- Harry Potter and the Philosopher's / Sorceror's Stone: Harry's accidental wizardry let a snake out of its case and (in the film version) trapped Dudley in it.
- Not exactly zany, but in one Animorphs book they go to the zoo and end up having to rescue a kid who falls in the crocodile pit. Rachel ends up discovering she's allergic to crocodile DNA (It Makes Sense in Context) It ends with a grizzly bear fighting a crocodile on national TV while scaring the crap out of an infuriatingly annoying teen star.
- Cassie's mother is a vet at the local Amusment Park/Zoo and the kids regularly go to get there to get new morphs since the very first book. Probably the most insane event was the time Tobias needed a Dolphin morph and decided to get it during the water show (his plan was to fly in and land on its back, being that he's a Red-Tailed Hawk and not a human). Much to his horror, the Dolphin was spooked by this and begins to get very hyper, the reverse of the norm when they acquire new morphs.
- Dr. Seuss's If I Ran the Zoo.
- Marriott Edgar's poems/monologues ''Albert And The Lion'' and ''The Return of Albert'', about the hazards of poking a lion in the ear with a stick.
- Many of Gerald Durrell's books are about amusing events in zoos; most notably, Menagerie Manor and Beasts in my Belfry.
- Malcolm in the Middle had a zoo episode. Highlights included Hal being bitten on the face by a tarantula during a demonstration (by Lois' Zookeeper ex-boyfriend), Reese antagonizing a goat (who gets revenge), and Malcolm and Dewey getting trapped in the tiger pit.
- The main characters of The Mighty Boosh are zookeepers (in series 1 and 2), and some episodes deal with a problem at work.
- The opening credits of the last three seasons of Threes Company featured the cast getting into wacky hijinks at the Los Angeles Zoo: Jack getting distracted by a girl and slipping into one of the animal cages, Larry caressing what he thinks is Janet only to find out it's actually an elephant, Furley imitating a lion's growl and getting a weird look from a kid nearby, etc. On a side note, these credits also feature a cameo appearance by John Ritter's son Jason Ritter, who was only one year old at the time.
- On Calvin and Hobbes, Calvin's family goes to the zoo and he gets lost. Surprisingly, not much actually happens beside that, although Dad does run a little faster when he imagines Calvin going into the tiger pit because he likes them so much.
- In homage to the storyline mentioned above, The Punisher video game has a level set in a zoo. You can reenact several of the deaths in the story, as well as some new ones like letting a thug killed gouged by a rhino, or tossing one into a tank of electric eels.
- This is pretty much the entire plot of the indie game, Fruit Mystery, where you feed different foods to zoo animals and read about the catastrophic results.
- DSBT InsaniT: This is the premise of episode 4, 'Untamed and Uncut'.
- There was an episode of The Replacements that had this as the plot. Riley replaces the zookeeper with someone who, she thinks, will take better care of the animals. She (the replacement) lets all the animals free. At the end of the episode, the animals are allowed to run free in a Golf Park, making it Hilarity In Golf Parks.
- There's the extremely controversial The Simpsons episode "Homer vs. Dignity," where Homer gets molested by a panda.
- Reverend Lovejoy rescues Ned Flanders from the baboon exhibit.
- Another episode has Bart taken in by a mother gorilla in the zoo.
- There is a very early Looney Tunes cartoon featuring Egghead (the precursor to Elmer Fudd), who eventually gets eaten by a lion—but we also take a look at all the other zoo animals as well.
- There's another featuring Pepe Le Pew where the animals react to his smell.
- And a third with Sylvester chasing Tweety all over a zoo.
- And a fourth one with Pepe Le Pew pursuing a wild cat that escaped from the zoo.
- An episode of DuckTales (1987) did this, when the Beagle Boys steal Gyro's furniture mover ray to steal Scrooge's money. Huey, Dewey, and Louie eventually find them but get chased away by the Beagle Boys, into a zoo. Hilarious antics include a gorilla being teleported between two lovers about to share a kiss, and an elephant being teleported in front of an elevator.
- There was the episode of The Ren & Stimpy Show in which they dressed as monkeys and lived at the zoo.
- One episode of King of the Hill deals with Hank being raped by a male dolphin at a Sea World-esque park.
- A vintage Popeye cartoon has Swee'pea cheerfully running loose among a zoo's animals with Popeye in frantic pursuit. After Popeye rescues Swee'pea, he gives him a cute monkey-on-a-stick toy that makes him scream in terror, just as Olive comes to pick him up.
- Beavis And Butthead join a zoo tour, hoping the guide will talk about the animals "doing it", which she only does after they leave in boredom. While they're in the reptile house there's a momentary power outage that gets them in a panic, and when the lights come back on they're in a compromising position, inadvertently holding each others...snakes.
- In The Flintstones, the title family and the Rubbles go to the zoo and of course Fred finds himself in the gorilla cage while everyone is too entertained by him being chased around to help him until Bamm-Bamm gets him out.
- Every episode The Penguins of Madagascar takes place in the Central Park Zoo.
- In Avatar: The Last Airbender, Aang visits a zoo in Ba Sing Se. The animals are all in small cages and the zookeeper explains that the city won't give him any more money because nobody is visiting, so he can't improve conditions for the animals. Aang suggests building a new zoo outside the walls of the city, and offers to take the animals there himself. After all, he's the Avatar, so animals will listen to him! Naturally, Hilarity Ensues as he tries to lead a massive group of wild animals outside of the city.
- In one episode of The Angry Beavers, Norbert gets arrested for a crime Dagget committed and sent to a zoo, which turned out to be a 5-star resort for animals.
- Grojband: In "Zoohouse Rock", Trina persaudes Mayor Mellow that Grojband are actually musical bears and he cages them as the zoo's newest attraction. Their attempts to free themselves result in a riot where the townsfolk release all of the animals to run wild through Peaceville.
- At least three cartoon shows as a whole center around zoo antics: Hanna-Barbera's Wally Gator and Help!...It's the Hair Bear Bunch!, and Leonardo-TTV's Tennessee Tuxedo and His Tales.
- Several examples of people being killed or maimed by zoo animals through blatant stupidity have made it into the Darwin Award.
- Zookeepers take it in stride when carnivorous animals supplement their human-provided diet with whatever wild birds or rodents might wander into their exhibits: while it does put them at some risk of parasites, it's also a serendipitous form of enrichment for such captive predators. To zoo guests, it can look like this trope when a bobcat pounces on a live chipmunk that scurried under its fence or a polar bear drags down a goose that unwisely paused to rest on its exhibit's moat.