In a tire commercial, a driver brakes suddenly to avoid running over a beaver. Returning to the same road in a rainstorm, he brakes to avoid hitting a tree that falls in his path. Looking out the window, he sees the bridge up ahead being washed away, as the beaver (who's just saved him from an unplanned swim) salutes him from beside a gnawed-through tree stump.
Anime and Manga
Futari wa Pretty Cure, episode 6, a bear cub rescued by Nagisa stands between the girls and its demon-possessed mother long enough for them to figure out a plan.
In one episode of Azumanga Daioh, a young wild cat Sakaki had befriended in Okinawa tracks her all the way back home after its mother dies, and shows up just in time to save her from a pack of cats led by Kamineko.
Momo-chan, the dolphin that Lucia and her friends free early in Mermaid Melody Pichi Pichi Pitch, shows up later to take Kaito to bail them out at Lucia's palace.
A lot of Ash's Pokémon tend to be acquired in this fashion. As well, there's Ash's Charizard, who was completely disobedient until Ash saved its life, again.
In Pokémon Special, Pearl helps a Luxio redeem itself in front of its pack and it eventually ends up saving his life twice before officially joining his team.
A bunch of Unown that the Sinnoh trio rescue later helps Pearl break into the Veilstone Galactic Building by performing a Zerg Rush to distract the guards.
Natsume Yuujinchou - An extremely powerful Youkai jumps to Natsume?s defence against an evil Ayakashi, because Natsume helped him earlier in the episode. This is a pretty big reward considering all Natsume did was cover up a puddle in the road so that his servants could pass ? despite the fact they could just as easily have walked around it...
Koihime†Musou subverts this as a running gag, with Chouhi keeps bumping into the animals her father saved, supposedly - only to discover too late that they aren't.
The lapins in One Piece. During the Drum Island arc, Luffy pulls a mother lapin free from the snow after an avalanche. Later, the lapins protect Luffy from attacking villains. Unfortunately, while allowing Luffy to get his True Companions to safety, they end up viciously beaten for their trouble.
In an early issue of the No Need For Tenchi manga, Sasami finds and tends to a wounded wolf that had escaped from a truck, whom she affectionately calls "Doggy". It protects her from a group of wild wolves and, many years IRL-time later, returns to help tend to a group of abandoned raccoon cubs in her school.
Played darkly in the Valley Forge, Valley Forge arc of The Punisher. A group of soldiers have been tasked by to bring down Frank Castle, knowing he won't use deadly force against them, by a cabal of corrupt U.S. generals. In the end it turns out that the Colonel tasked with leading the soldiers was once a soldier in Vietnam who had been rescued by Frank's Marine Recon squad. When the generals come around to view their "prize" they find an untied Frank with a fully loaded 1911. You can guess what happens next.
Mildly subverted in that the Colonel may have also covered up their corrupt generals' crimes in the process, and that Frank Castle wanted them dead more than he wanted their crimes exposed.
Shows up in Bone, where the heroes befriend a baby rat creature whom Smiley Bone names "Bartleby". In part because it's dangerous for a rat creature to be near humans, in part because they figure he belongs with his own kind (never understood that reasoning when "his own kind" is Always Chaotic Evil), they manage to get him back in the company of rat creatures. Of course, later on, when they need the help, one of the rat creatures turns out to be Bartleby, and by the end he's their travel companion for keeps.
In Golden Fish an old fisher catches a titular Golden Fish who asks him to let it go and promises all kinds of favors in return... We-ell, it didn't work out eventually, but it was not its fault.
In Frog-princess while on his quest to free the imprisoned princess from evil Koshey, Tsarevich Ivan encounters various animals and intends to kill them to eat but then changes his mind every time. They later help him to obtains Koshey's Soul Jar.
In Magick Rng the main hero literally gives a shirt off his back to buy out a dog, a cat and a snake from a cruel owner. That works out PERFECTLY!
In Golden Antelope a boy helps all kinds of animals, getting transportation, guidance, protection and even fundraising in return.
In The Golden Mermaid, the prince actively offers his horse to the starving wolf, and gets its aid.
A traditional tale of the Kamba people from Kenya tells the story of a man who cultivated a field. The crops attracted gazelles so he put traps to defend his crops. One day he saw a lion had felt on one of the traps. He freed the lion after making him promise that he would not hurt him. Once free, however, the lionattacked him. Then the man convinced the lion to let him go after promising that he would give him the heart of every animal that fell on his traps from then on. One day his wife accidentally fell on one of the traps, and just as the man ran to free her the lion appeared and demanded the wife's heart as part of their agreement. The man refused saying that this wasn't part of the deal, so the lion killed the wife and badly injured the man. Moral of the story: Don't trust lions. They f*cking eat people.
In Friendship Is Magic: Prime: Act III, Fluttershy saves an Insecticon from getting eaten alive by a Scraplet, and the Insecticon (which she names Bob) becomes ever-faithful to her.
In several Harry Potter fanfics like the Danger Verse universe or the Alpha series, Harry helps the basilisk in the Chamber of Secrets to survive (instead of killing it as in the books) or to get rid of Riddle's influence, and the basilisk ends up helping defend the castle.
In The Jaded Eyes SeriesHarry/Tristan befriends Alucard after giving him a bite to drink and freeing him from the alchemical leash put on him by the Hellsing family.
George Lucas claims in the commentary for The Empire Strikes Back that Yoda is based on a myth about a magical frog that sits on the side of the road, teaching things to people who are kind to him.
Also, behind-the-scenes footage of filming the Ewok village scenes in Return of the Jedi show Lucas also intended a similiar idea for that movie. Since Luke convinces the others not to harm the Ewoks and surrender, they return the favor by saving the Rebels from the Imperials during the planetside part of the final battle.
D'leh in 10,000 BC had second thoughts before his concern over an about-to-drown Sabretooth Tiger led him to release it from where it was pinned under some trees, since falling rain would quickly drown it. For the record, it saves his and his father figure's asses later and marks him as The Chosen One to bring down The Empire. It's nice to know PETA has long roots in history.
The Bandersnatch in Tim Burton's Alice in Wonderland helps Alice after she gives it back its disembodied eye, by licking the scratch wounds it inflicted on Alice's arm earlier and healing it, lest it (quoeth Cheshire Cat) "festers and putrefies". It later serves as her mount in the Final Battle against the Jabberwock.
Two Brothers has two tigers that fail to attack the humans that used to own them, even though everyone else is convinced the tigers are dangerous.
Natty in The Journey Of Natty Gann befriends a wolf by opening a door for it to escape a dogfight and later giving it some of her food. The wolf subsequently returns the favor by bringing her a freshly-killed rabbit when she's lost and hungry in the woods, and accompanies her for most of the rest of her travels.
In Crank High Voltage, Chev Chelios saves a dog that was being tortured by two assholes with a Shock Collar. The dog returns the favor by assaulting someone who was about to attack Chev from behind.
Hiccup and Toothless in How to Train Your Dragon. Hiccup downs Toothless with a catapult, and initially wants to kill him, but realizes the creature is just as scared as he is. They befriend each other and Hiccup invents a rudder-like device to function as a tail for Toothless, since his is partially damaged/deformed.
In The Living Daylights, James Bond and Kara fight their way out of a corrupt prison in Afghanistan. While escaping, they free the prisoner in the next cell on a whim. The prisoner turns out to be a leader of the Afghan Resistance, and becomes a valuable ally.
A variation in The Avengers: Tony Stark's kindness towards Bruce Banner, and his lack of fear and suspicion of the Hulk, pays off later on, when the Hulk, previously described as a "mindless beast" consciously and deliberately saves Tony's life during the final battle.
Played with by Terry Pratchett in the Discworld novel Small Gods. The hero saves a predator, who (now bound by Narrative Convention to do the Androcles) tracks the hero down to symbolically not kill him. However, as is noted, other people didn't save it, and so are fair game.
Kit removes a bit of wreckage from around the axle of a sentient Lotus in the Young Wizards novel So You Want To Be A Wizard, and the Lotus ends up becoming a friend and helper to them.
The Book of Three (1964), the first of Lloyd Alexander's Prydain novels. Taran helps a wounded baby gwythaint (a species of gigantic dangerous bird creatures forced to serve the Big Bad Arawn). The favor is repaid twice; once in the first book when the gwythaint tells Gwydion where to find Taran and the Horned King, and more significantly at the end of the fifth and final book.
In Watership Down, this is invoked by Hazel, who realizes that the rabbits will need friends and allies in their new home. It ends up earning them the friendship of a mouse, who tells them about a good feeding place, gives them information on the proximity of men, and gives them advance warning when the Efrafans come to attack; and later nets Kehaar, a gull, as a very useful ally and scout.
In one of the El-ahrairah stories (The Story of King Fur-Rocious) in Tales of Watership Down, on his quest to win a nearly hopeless war against the titular King, El-ahrairah befriends a cat (who jumps into his ear), saves a flock of crows (who also jump into his ear), helps out a nest of ants (into the ear again), and even enlists the help of a river (the other ear, this time). This pays off when, on three consecutive nights, El-ahrairah challenges the King and is shut up with the Rabid Rats (taken care of by the cat), the Wildcat Weasels (killed by the crows), and the Savage Stoats (chased off by the ant nest). The fourth night, King Fur-Rocious decides to have El-ahrairah tied up next to his sleeping place so he can figure out what's going on. For his pains, he eats the full might of the river, and promptly leaves thereafter. That was the only war El-ahrairah ever fought, and that was how he won it. My question: How big are his ears, anyway?!
In "The Fox in the Water", El-ahrairah altruistically gives advice to many creatures. A snake he helps, having heard of his other deeds, gives El-ahrairah the power of hypnotic eyes temporarily, which he uses to defeat a family of foxes that had been causing problems for his warren.
In the Harry Potter books, Harry frees a House Elf named Dobby. Many books later, Dobby makes a Heroic Sacrifice to save the lives of Harry and his friends when they are imprisoned and trying to escape.
In Jean Auel's Earth's Children series, Ayla adopts a cave lion and raises it from a cub. Later on, after the same cave lion kills Thonolan, she's able to calm it down and preventing it from killing Jondalar. Also, she saves the life of someone else in a similar fashion in the next book (same lion).
He's only called "Gar" by Richard until he tells Richard his real name, "Gratch". And once Richard realizes Gratch's intelligence, he's more of a friend than a pet.
Don't forget Scarlett the Red Dragon and her son. Richard helps Scarlett rescue her egg (which Darken Rahl was using to force her into servitude). Scarlett (and her son) later aid(s) Richard several times at critical junctures throughout the series when a dragon of her species would ordinarily just eat him regardless.
In Beyond the Deepwoods, Twig removes a rotten tooth from a mouth of a Banderbear, a species normally nonthreatening but not very social, and befriends it, and even after it dies, he keeps the tooth as a charm and manages to more or less befriend the whole species.
Psmith tells a version of this story in Mike and Psmith, although he seems to believe that it was a pterodactyl Androcles encountered.
In Snow Crash, Y.T. shows kindness towards a Rat-Thing, a monstrous cybernetic killing machine. This, as well as taking care of a stray dog with a bullet wound, results in some Laser-Guided Karma at the end of the book.
It might not apply, but in The Jungle Book, Mowgli's ability to remove painful thorns from the paws of his wolf pack brothers makes him a popular fellow among them. At the same time, however, this is seen as a point of shame among some of the wolves; a fact which Shere Khan uses to turn the pack against Mowgli.
Subverted in the Chinese short story The Story of the Zhung-Shan Wolf by Ma Zhung-Shi: the wolf pleads a scholar to conceal him from a hunting party, promising to be grateful afterwards. When the hunters are gone, the wolf reveals its true nature and threatens to devour the scholar. Luckily, an old wise-man passes by and tricks the wolf, which the scholar then kills.
In The Message, fourth book in the Animorphs series, the kids help a humpback whale that is being attacked by sharks. At the end of the book, the whale shows up and drives off Visser Three (who was attacking the kids in the form of an alien sea-monster).
This trope is recycled in the thirty-ninth book, The Hidden, which is perhaps not-so-coincidentally another Cassie book.
The Hobbit. The Eagle saves Gandalf, Bilbo, and the Dwarves because Gandalf once helped him heal his wounded wing.
In the Lords of Deliverance book "Eternal Rider'' by Larissa Ione, Cara Thornhart earns a hellhound's love and respect after she heals it from a bullet wound.
Firebird Lackey: Ilya gets help from a horse, nightingale, fox and the titular Firebird by saving their lives (or tasty apples, in the horse's case).
Live Action TV
Bernard's Watch: the eponymous Bernard used his time stopping watch to remove a tack from an old man's foot. When he is later sent to the new Headmaster, a Mr Lion, who turns out to be the old Man, and instead helps Bernard escape punishment.
Grimm: Averted in "Last Grimm Standing" where Monroe helps pull a nail out from the hand of a gladiator shortly before they are set to fight each other. But the gladiator had no problem trying to kill Monroe and probably would have if Nick didn't intervene.
House: In one episode, House heals his crazy cellmate's pet cricket that got sick from a pesticide. Towards the end of the episode, when another inmate is about to stab House with a knife, House's cellmate bashes the other guy in the head with a chair.
Merlin: Inverted, in which it is the dragon who gives advice and aid to Merlin whenever he's in trouble, and eventually extracts a promise from him that he'll eventually set him free from the dungeon under the castle. When Merlin finally gets around to destroying his chains, the dragon promptly lays waste to Camelot.
Power Rangers Operation Overdrive: Invoked when Tyzonn the Mercury Ranger removes an improbably long spike from the foot of Norg, a Yeti sharing his cave with one of the Big Bads. While it does mark the beginning of Norg's shifting loyalties, the fact that he hardly counts as a villain to begin with makes it more a case of ButtFace Turn.
Revolution: Averted Trope. The bounty hunter Charlie persuades Miles to spare later on hands them over to the militia. Later, Danny manages to save Tom Neville from certain death and still ends up being rearrested.
Scrubs: Referenced in an episode, when JD removes a splinter from the Janitor's toe (though he mixes it up slightly with the story of the mouse and the lion). When JD tries telling it, the Janitor cheerfully cuts him off with "Oh yeah, and then the lion kills and eats him anyway!" Funnily, the Janitor does try to repay JD with unwanted help, causing JD to waste the favor by asking the Janitor to do something trivial. The Janitor notes afterward that JD could have asked to not be hassled for a year.
Sinbad: In the 2012 miniseries, Sinbad gives water to a chained-up Roc, for which it lets him pass and leave his prison, and later gets the key to its chains and releases it. In return, it saves him from a probably fatal fall, capsizes a boat full of people out to kill him, and beats its wings to provide enough wind for his ship to get on its way.
Stargate Atlantis: The story is referenced by the main characters. Sheppard and Teyla get kidnapped by a wild-looking man who has a Wraith tracker implanted in his back. Sheppard gets the expedition doctor to remove it and in exchange, the wild-looking man, Ronon, attempts to capture a member of the team who had gone AWOL. He fails, but eventually joins the expedition.
Also in 'Stargate Atlantis'', Sheppard is kidnapped by Genii and imprisoned along with a Wraith. They form a truce with each other long enough for the pair to escape, and later the Wraith, "Todd", becomes a valuable ally in the fight against all the Wraith hives, and a (relatively) moderating influence within his own.
Stargate SG-1: Daniel Jackson makes reference to this story during an episode when he is the captive of an injured Unas and helps its recover from its wounds. Along with other interactions, this develops into a sort-of respect, and the Unas saves his life.
In a tale about a frog princess, the hero successively spares a bear, a rabbit, a duck, and a pike, and gets help from each of them at the end of the story to get Big Bad Koschei the Deathless' Soul Jar: The bear tears down the tree, the hare kills the hare, the duck strikes the duck, and the pike retrieves the egg from the pond it had fallen into.
One of the most frequent plotlines in the entirety of ancient folklore, to judge by the number of times it pops up in Grimm's Tales and other sources. Typically, while on his way to rescue the princess, the hero assists several small critters in succession; later, when the villain places seemingly-impossible tasks in his way, the grateful critters return to complete them for him (for instance, when charged with sorting an enormous heap of mixed grains, the hero of one tale is helped by the ants he'd rescued.)
In the old tale "The Golden-Headed Fish," an Egyptian prince is sent on a mission to capture the title animal, which is the only thing which can save his father from a deadly illness. He succeeds, but can't bring himself to kill the beautiful creature and sets it free. His father (who recovers anyway) banishes him from the realm. Out in the world, he encounters a strange man who wishes to work as his servant, and accompanies him on a number of adventures, saving his life frequently. After the prince's father dies, his mother summons him back to take his rightful place as king, at which time the servant requests permission to leave.
Prince: If it were not for you, I should long ago have been dead.
Servant: And if not for you, I too should long ago have been dead. For I am the golden-headed fish.
St. Jerome also tames a lion by removing a thorn from its paw.
There is a story that says that when when King David was on the run from King Saul, he went to hide in a cave, where he saw a spider he was going to kill, before the spider could stop him, saying he’d help him somehow. King David laughed, but spared it anyway. The spider formed a web around the cave’s opening, so when King Saul came by the cave, he said there is probably no-one in there, as they’d have to tear through the cobweb to get in. He left, and King David blessed the spider.
An almost identical story is told of Muhammad, albeit different in an important way: the cave that he and his friend Abu Bakr were hiding in during the Hijra (flight from Mecca to Medina) had a spider in it, which Abu Bakr was about to absentmindedly kill but which the Prophet had him spare. The spider made a cobweb over the opening, and some birds nested, leading Quraish (the pursuing Meccans) to look elsewhere.
A similar story tells of how King Solomon was stung by a bee once and wanted to kill it, but it asked him to spare her so she’d help him some day. King Solomon reacted the same as David. Later, when the Queen of Sheba came over to test King Solomon’s famous wisdom, she asked him to pick the real flower out of three―the other two were impeccably fabricated. The King was stumped, when the bee came over and sat on the real flower. (So apparently the bee gave her life for the hell of it, and made a heroic sacrifice to make amends.Ah well.)
Subverted in The Hairy Ape—the ape in question kills the main character after he frees it.
George Bernard Shaw's Androcles and the Lion plays this as straight as you'd expect from the title.
Subverted in Wicked: as a student at Shiz, Elphaba (who will later become the Wicked Witch) rescues a lion cub from experimentation and frees it from its cage. This cub grows up to be the Cowardly Lion, who apparently holds Elphaba responsible for his cowardice and helps Dorothy and the Tin Man to hunt her down.
Early in Resident Evil 4, Leon Kennedy encounters a wolf (though Leon calls it a "dog") caught in a trap. If the player has him free the wolf, it returns later to help Leon fight his battle against the first "El Gigante" boss by distracting the monster.
At the end of Super Metroid, the baby Metroid which Samus spared at the end of Metroid II sacrifices itself to rescue Samus from Mother Brain.
This is a bit more justified than most examples: the Metroid imprinted on Samus when it hatched, causing it to see her as its mother. Naturally it would try to defend her against danger.
Metroid also has an example that transcends games with the Etecoons and Dachoras. In Super Metroid, they were friendly creatures who helped Samus by teaching her techniques like the Wall Jump and the Shinespark. At the end of the game when you're trying to escape the Zebes-Shatttering Kaboom, you can take a slight detour to find them trapped in a room with rising acid. You can then blast a hole in the wall that allows them to escape, and if you do so you'll see a tiny dot escaping the explosion in the ending sequence.
Later on, in Metroid: Fusion, you'll find them in a containment hold in the BSL labs partway through the game, and you set them loose. At the end of the game, Samus sets the BSL space station on a collision course with the planet SR 388 in order to wipe out the X Parasites once and for all, and has about three minutes to escape before impact. She heads to the docking bay only to find that her ship is not there. She soon discovers the reason: an Omega Metroid comes crashing through the wall in order to serve as the Final Boss. After she defeats the Omega with the help of a Villainous Rescue by the SA-X, the Etecoons and Dachoras return the favour she provided on Zebes by piloting her ship into the docking bay (with the help of her computerised CO, Adam), allowing her to escape the station just before it made planetfall.
Speaking of Samus, Pikachu plays this role with her in Super Smash Bros. Brawl. In the Subspace Emissary story, after she rescues him from a generator, he accompanies her through the enemy base, helping her get her suit back, and finally saving her ass when Ridley tries to smear her across the wall.
Granted, Pokemon appear to be sentient anyway. Trainers who treat their Pokemon well can expect to be treated well in return.
In the same game, you are required to feed a starving eagle on the mountain range when you only have two food rations left. Failure to do so means he won't save you from the Roc that plucks you away at the end of the chapter.
The early part of the game contains several animals in need; helping them will result in their returning the favor later on.
Averted in Exile and the first three Avernum games. There are a few minor encounters where freeing a trapped monster will result in said monster trying to kill you because they're "nowhere near bright enough to comprehend the idea of gratitude." However, the later Avernum games do toss in a few hungry animals who will follow you around briefly and help during fights after you feed them.
During an early stage in Star Tropics, Mike rescues a dolphin. At the end of the game, the dolphin saves him, taking him back to C-Island.
Played straight in Crusader of Centy, where many of your animal companions must be saved from a horrible fate. Three were held captive by bosses, and two were hopelessly stuck somewhere awaiting death.
In the first Clock Tower, Jennifer can rescue a crow from being imprisoned in the Barrows Mansion. It's the only way to achieve one of the better endings when Mary tries to kill Jennifer at the top of the clock tower, but is assaulted by a group of crows who cause her to fall to her death.
They can also attack Bobby (if he's chasing Jennifer) if you lead him into the room you free the original crow from.
Inverted quite magnificently in Ōkami: the player is the wolf (actually Amaterasu, goddess of the sun) who runs around assisting helpless villagers — in her time of need they restore her to strength and health by praying for her.
Commander Shepard has the option of letting the last Rachni queen go free.[[spoiler: She's captured again in Mass Effect 3, this time by the Reapers. Shepard can once again set her free, leading the Queen to send Rachni workers to aid in the construction of the Crucible project.
In Terranigma, early on, you help Liam, a young lion cub, pass a test - to descend into a valley of death, and return alive. Later on, after Beruga wipes out Neo-Tokio with a bio-weapon, you encounter a girl in the sewers being menaced by a lion. Guess who it is!
Inverted and then played straight during Liam's escorting mission, as the monster that acts as the stage boss pleads for its life and offers a "treasure" to Ark if he lets it go. The treasure chest is a booby trap, but before the monster could catch Ark off guard, Liam kills it offscreen and then guides Ark back to the safety of the lion den, where his kin welcome Ark as one of them.
In the SEGA Shadowrun game, Joshua saves Licourtrix, a dragon, from a squad of hunters sent by Renraku. In thanks Licourtrix offers Joshua a scale, which is needed by a shaman to cast a spell. He also pulls a Big Damn Heroes moment during the final battle, binding Thon with his magic and offering Joshua a strategy to destroy him.
So the inverse of "Never Cut a Deal with a Dragon" is "Always have a Dragon owe you a favor"?
Even before that, all of the monkeys that he saves in the same dungeon are quick to return the favor, proving themselves to be vital to progressing through said dungeon and, ultimately, reaching Diababa's lair.
In Fallout 3, you come across a dog and a wastelander fighting some raiders in a junkyard. The wastelander always dies, but if you save the dog's life it becomes a useful companion.
Torg does this for the demon Mosp in thisSluggy Freelance strip. This ends up saving his life when the "That Which Redeems" arc roles around.
One of the rare worksafe pages of Oglaf deconstructs the "kindly hunter" version of the story. The hunter releases a deer, a rabbit, and a sandwich upon their requests, and then keels over and starves to death. In the last panel, the creatures gather around his grave and wonder if there wasn't something they could have done.
In "Dog of Death," Santa's Little Helper takes on the role of the fearsome, bloodthirsty lion who shows mercy when he refuses to attack Bart, on Mr. Burns' command – and in the process, drives off the other dogs and turns them into whimpering cowards. This is despite the family treating SLH like dirt as they struggle to regain their financial footing to pay for emergency surgery on the dog.
In another episode, Homer tells Bart the story of "Hercules and the Lion." Hercules is able to pull a thorn out of a lion's paw, and the lion in turn grants him riches. When Bart points out the obvious flaw in that story and asks how a lion could somehow get rich, Homer simply replies that it was back in "the olden days."
However, it's double-subverted in an episode of Buzz Lightyear Of Star Command, where Buzz and his zoologist love interest help a dangerous predator... which, despite Buzz citing the Androcles myth, immediately turns to try to eat them. Afterwards, the zoologist even chastises Buzz for being irresponsible for expecting human behavior from a wild animal, instead of accepting it as it is. It still does help them later in a moment of need — keeping it from being a full subversion — but this is treated as entirely coincidental, with Buzz's assumption that it's "returning their kindness" being overly romantic.
Road Rovers, "Where Rovers Dare". While the Rovers are busy stopping a weapons dealer from starting a War for Fun and Profit, Colleen takes in, and fixes up, an injured wolf. While the bad guys have cornered her and her all-male teammates, the wolf howls and next thing you know tons of wolves have shown up, allowing the UN to easily capture the baddies.
Fractured Fairy Tales on the Rocky and Bullwinkle show had an episode titled Androcles and the Lion. Unfortunately, by the time Androcles met the lion in the arena it'd been starved by the Romans, and the score was soon Lion:1, Androcles: 0.
Codename Kids Next Door: Numbuhs 2 and 3 adopt a baby skunk. Although Numbuh 1 doesn't like this, it ends up helping them in their mission to infiltrate a camp, and even makes a Tomato Surprise cameo in another episode two seasons later.
The skunk's parents also play this Trope. They reward the KND for keeping their son safe by showing up and saving them when they're in trouble.
A version of this happens in the Looney Tunes short Roman Legion-hare. After chasing Bugs Bunny through the lion cages beneath the Colosseum and in the process infuriating all the lions (and being comically mauled a few times), Captain of the Guard Yosemite Sam throws Bugs into the arena so that Nero can watch a victim be eaten. Instead, the lions rush past Bugs, jump up the stands, and go after Sam and Nero. Although in this case, it's not because Bugs was friendly to the Lions, but because Sam was cruel to them.
Well, Bugs was a little friendly to them. When Sam tried to cross the pit using stilts, mocking the lions with insults, Bugs threw them some axes and saws, which they quickly used to dismantle the stilts.
Spike the Bulldog was usually the "lion", who would protect Jerry from Tom after Jerry got him out of trouble. In one short Jerry pulls a tack out of Spike's paw, a deliberate call-out to the old Aesop fable.
A truly bizarre variation occurs in Tex Avery's MGM cartoon "King Sized Canary"; as a hungry cat stalks a mouse, the mouse says, "Hey, I just sat through this picture, and if you're smart you won't eat me, because later in this picture I'll save your life." He does too.
Diego the sabre-tooth cat in Ice Age does a Heel Face Turn after his soon-to-be True Companions save him from falling into lava. Granted, most characters were animals, but Diego was the only carnivore protagonist.
In the final episode of the Jumanji cartoon series, the kids figure out that Allen has to pull out a thorn from a lion's paw to escape from Jumanji once and for all.
This was the plot to one of The Ant and the Aardvark cartoons, where the Tiger agrees to protect Ant and his gang from the hungry Aardvark after he pulled a thorn off his foot. In the end, the Tiger steps on another thorn and this time the Aardvark pulls it off. You can guess what happens next.
And few years earlier this happened with The Pink Panther. A man pulls a nail off of the Panther's foot and he becomes his slave. The man was annoyed at first but found helpful when he realized that he can use him to scare his shrewd wife and her mother. After many attempts at getting rid of the pink cat, the wife gives up and decides to leave home... only for the Panther to step on another nail, with the wife pulling it out of his foot. Again, you can guess what happens next.
"A Small Matter of Pygmies". A pygmy is being punished by the other pygmies by being tied to a stake so he can be eaten by a panther. Race, Jonny, and Hadji save him by shooting the panther and releasing him. When they're captured by the other pygmies, he returns the favor by releasing them.
"Treasure of the Temple". The Quest team releases an Indian who had been staked out to die by the Big Bad and his mooks. When the team is captured by the Big Bad, the Indian gets them out of their cell to freedom.
American Dad: Roger apparently raised a wolf from when it was a cub and released it in the wild, and later, finds a wolf while he's stranded with the family in the middle of a desert (which is owned by Stan's cousin). It's not thesame wolf.
At the end of the Batman The Animated Series episode "Avatar", Ra's al Ghul leaves Batman stranded in the desert. Ra's enforcer, Ubu, who was grateful that Batman saved his life earlier, passes him a canteen.
In one episode of the 2002 He Man And The Masters Of The Universe, Prince Adam frees a dragon that was buried by a cave-in. Later, He-Man is fighting some dragons and is nearly killed. The dragon from earlier (the mother of the other two) recognizes him from his scent and calls her children off. Then, when Skeletor attacks Greyskull, she later comes back to help him.
The mother dragon comes back in a later episode, helping He-Man again, when a crisis happens that requires him to tranverse Eternia faster than Battle Cat can handle. Fortunately, she can fly much faster than any landbound mount can.
There was an old Conan The Barbarian series that played this up. In one episode, Conan encounters a dragon that acts much like a genie (Conan fond a MacGuffin, and the Dragon had to swear loyalty and grant wishes to whoever held it). When the Dragon calls Conan "Master", Conan declares that he is master of no man... or beast, and tells the Dragon he is free. Fast forward to the end of the season and the giant climatic battle, the Dragon appears out of nowhere to aid Conan and his allies.
In the "Commander McBragg" segment of Tennessee Tuxedo And His Tales, McBragg has a story like this, and it's one of the few times he has actual evidence to prove it. According to him, he is captured by "stange men" after his plane crashes in a remote valley, and left as a Human Sacrifice to appease a giant who is angry. McBragg quickly discovers that a thorn is lodged in the giant's foot, and that he's not angry, but in pain; so he dislodges the thorn, gaining the giant's friendship. (The proof? A large, metal ring that the giant gave him from his little finger, which McBragg now uses as a hula-hoop.)
Also, it is thought that this sort of thing may have been how the first pets were domesticated.
This is actually somewhat understandable, as predators will often try to pick off one of the weak or injured ones, since they're easier to get. Evolution dictates that animals will predictably become hostile to other animals when injured.
Wojtek, the solider bear. During World War II, some Polish soldiers bought a (abandoned) bear cub during their stay in Iran from a local boy. After raising him and taking him with them on their deployment to Italy, Wojtek helped the soldiers carry artillery ammo.
Truth in Television, though what degree depends on the animal and the circumstances. The extreme loyalty of some dogs is particularly noteworthy—there's a reason dogs are called Man's Best Friend.
In humans, this is an instinctive behavior that manifested due to the obvious benefits it provides. Since you aren't always at the top of your game, and you are not infallible, having someone go out of their way to help you is a HUGE bonus in your survival odds—and returning the favor keeps that relationship going for both individuals.
Played disturbingly straight during the Columbine Massacre, when Eric Harris encountered Brooks Brown. Harris instructed Brown to leave the school, citing their recently created friendship. Minutes after this, Harris and Klebold would go on to murder 13 people.
Subverted (and double subverted) in a classic joke. A man saves an elephant with a thorn in its foot. The elephant takes a long look at the man and the hurries off. Some years later, the man sees the elephant in a local circus. Since elephants never forget, the man decides to enter into the elephant's enclosure to comfort his old friend the elephant. He is promptly crushed to death, at which point the narrator usually points out that it was probably not the same elephant.