Arguably, Chris Parker in Adventures in Babysitting. OK, she's the babysitter, not the mom, and two of the kids aren't that much younger than Chris herself. Still, a suburban teen takes on several inner-city gang members to defend her charges while in the way to help her best friend. Successfully. With verbal intimidation alone.
Chris:[grabs the Lords of Hell gang leader's knife and points it at him] Don't Fuck with the babysitter!
Pictured on the main page: Ellen Ripley of the Alien series was always a competent character with a decent survival instinct.Threaten her quasi-adoptee girl Newt and then, well, she's duct-taping weapons together to make a BFG, single-handedly invading the aliens' nest and strapping into a Power Loader to take on the Alien Queen in the mother of all catfights. Say it with us: "Get away from her, you bitch!" And considering that Ripley had killed a number of the Queen's offspring as well, it qualifies as a Mama Bear Showdown.
Elaine Miller in Almost Famous, when she's on the phone with Russell Hammond, the rock guitarist whose band her son William is touring with:
Elaine: If you break his spirit, harm him in any way, keep him from his chosen profession which is law - something you may not value, but I do - you will meet the voice on the other end of this telephone and it will not be pretty. Do we understand each other?
Russell: Uh, yes, ma'am.
Elaine is based on Cameron Crowe's mother, who apparently had conversations like this with rock stars in Real Life.
Animal Kingdom contains an evil example in the shape of Janine, grandmotherly matriarch of the criminal Cody family and fiercely protective of her sons to the extent that she arranges for her grandson Joshua to be killed after he threatens to testify against them.
Martha Kent provides a touching non-violent variation in a Flash Back in Man of Steel. Clark is having a Sensory Overload at school and hides in a closet and uses Heat Vision on the doorknob when the teacher tried to open it. Martha comes into the school and instead trying to force her son out, she soothes him telling her to focus solely on her voice and make the world small. Clark soon calms down, and opens the closet to hug his mom. Martha, in addition to helping Clark manage his powers also made sure a Brightburn situation was thoroughly avoided.
In Batman v Superman: Dawn of Justice, Martha Wayne is depicted as this along with her husband Thomas being a Papa Wolf, as she attempted to wrest the gun away from the mugger that killed Thomas and would kill her to protect Bruce.
In Birds of Prey (2020), Harley Quinn, Black Canary, Renee Montoya and Huntress all have a Mama Bear instinct towards Cassandra Cain whom Black Mask is after. Harley in particular goes on several One-Woman Army rampages against goons to protect her.
Crosses into Becoming the Mask in Big Mommas House 2, where FBI agent Malcolm ends up going against orders because of his promises to the Fuller children he made as Big Momma.
The Blind Side: "You threaten my son, you threaten me. You so much as cross into downtown, you will be sorry. I'm in a prayer group with the D.A., I'm a member of the NRA, and I'm always packin'."
The makers of Chang, a 1927 documentary about life in Thailand, staged most of the action for the cameras—a common tactic for documentaries of the day. In one scene they separated a mother elephant from her cub, and tied up the cub to the raised hut that was part of the set. The mama elephant was released offscreen, and as the filmmakers anticipated, it charged in and freed its cub. What they didn't anticpate was the mama elephant then proceeding to tear the hut to pieces.
Dark Night of the Scarecrow: This 1981 made-for-TV chiller has Jocelyn Brando (yep, Marlon's sister) as Gentle Giant Bubba's mother - loving, protective, and lots more badass than his tormentors.
In Dracula Untold, Mirena stands up to defend her son Ingeras when he is threatened by the Turks.
If a character played by Jodie Foster has a child or a teenager in her care — do not threaten them! Movies like Flightplan (2005) (where her little daughter is abducted and petty much erased by a bunch of terrorists playing a Gambit Roulette) and Panic Room (where she and her teenage daughter, also an Ill Girl, have to protect themselves thee dangerous delinquents searching for something in their apartment's panic room) should make that very, very clear.
The Vietnamese movie Furie is basically Gender InvertedTaken meets John Wick. The main characters Hai Phuong is an ex-gangster who will stop at nothing to get her little girl back. As the child-trafficking gang would soon know, just because the furious mother doesn't have a gun doesn't mean she couldn't wreck her way through half of the country with just her bare hands and feet (and lots and lots of broken bottles).
Do NOT steal Mothra's egg and/or try to harm her larvae. She will unleash her rage upon you....Yes, even if you happen to be Godzilla. Mothra lost the fight. But she bought enough time for her larvae to hatch. Said larvae then proceed to hand Godzilla one of his few defeats ever by wrapping him up in silk.
This also happens in Godzilla Tokyo SOS in the Millennium era (with Kiryu backing her and her babies up). Though Mothra was still roasted alive by Godzilla.
Aside from GMK, Mothra has defeated Godzilla in every film they've been antagonists. Usually with help from her larvae or another monster like Battra, but in vs The Sea Monster she easily sends Godzilla tumbling with one smack of her wing. Being a protector of the Earth and its people (when they're not stealing her eggs or Shobujin), she'll take on any threat to defend them and humanity.
In Godzilla (2014), when the Female Muto realizes her nest has been blown up she immediately ditches the fight with Godzilla, and when she sees Ford nearby she puts two and two together and relentlessly chases him.
The British Kaiju film, Gorgo features a 200-foot tall monster that's nearly indestructible to all of man's weapons such as the military, bombs, fire, and electrocution, and is on a Roaring Rampage of Revenge all over Great Britain. Why? Because her child has been captured and is on display as a sideshow attraction at a circus for people to laugh at.
Grizzly Rage: A literal example. Four teens accidentally hit and kill a cub with their car and than stupidly go into the woods, where the mother bear that seeks revenge lives.
Kate McCallister from the first two Home Alone movies. When she finds out that she left Kevin at home in the first movie, she made it her mission to get back home to her son no matter what. In the second movie, she was furious with the hotel staff for losing Kevin and was willing to wander the streets of New York City at night to find her son. She reassured Peter that she would be fine, saying that the way Im feeling right now, no mugger or murderer would dare mess with me.
Homeward Bound: The Incredible Journey had a very literal use of the trope with Chance trying to "fish" with Sassy's help. The fish ended up getting close to some bear cubs. Chance, instead of giving up his fish, decided to scare away the bear cubs. The bear cubs then turned tail and fled from Chance's barking, and climbed up a tree screaming for their mother. Sure enough, while Chance was bragging about his victory, their mother approached Chance, not too happy with him for what he did and fully ready to kill him for it. Chance was just barely warned before he just barely fled.
Amusingly, the cubs were black bears while the "mother" was a grizzly bear.
Raksha in The Jungle Book (2016) to her adopted son Mowgli. She openly defies Shere Khan in his first appearance, calling him a "burnt beast", which visibly angers him. And later, she led the wolves to stand against Shere Khan and she manages to save Bagheera from Shere Khan.
Getting her entire wedding party ambushed and blown away by Bill and his assassins was bad enough. Getting the ever-loving crap beaten out of her by the assassins, followed by a bullet in the head from Bill himself, was bad enough. But when the Bride finally gets out of her coma after four years and discovers that the child that she was carrying is gone (and apparently dead), she decides to... well ...Kill Bill.
Also, The Bride may be a Dark Action Girl, but she does not like it when children (like Nikki and the ultimately alive BB) or teenagers (like Gogo or the young yakuza boy she spares) are caught in violent affairs. And she won't hesitate to say it.
The premise of The Last House on the Left is about a group of people who get trapped inside a house with a Papa Wolf and a Mama Bear after they brutalize and rape the couple's daughter. Three guesses as to what happens next.
In Lights Out (2016), it is Sophie seeing Diana trying to kill Rebecca in front of her that breaks Diana's control of her.
Sarabi in The Lion King (2019), as she challenged Scar's inconsistent story regarding the stampede, not only out of rage for the death of her husband Mufasa, but in defense of her son Simba when Scar accused him for it.
Sarabi: (defending Simba) Scar, you said that you didn't make to the gorge in time.
Scar: That's true.
Sarabi: (angrily) Then HOW DID YOU SEE THE LOOK IN MUFASA'S EYES?!!
(Scar stares coldly, realizing that he has inadvertently exposed himself as Mufasa's murderer)
Simba: (angrily) MURDERER!!!
This was the point of The Long Kiss Goodnight, where Geena Davis plays an ordinary, suburban homemaker/schoolteacher...until an escaped convict threatens her husband and child. Then it suddenly turns out that she's a former assassin with Easy Amnesia, and she proceeds to kick his ass seven ways to Sunday. Towards the end of the movie, she's taking on a terrorist-organization-backed-by-CIA single-handedly to save her daughter.
The Lost World: Jurassic Park combines this with Papa Wolf, showing that the mated T. rex couple are fiercely protective of their offspring; the human protagonists quickly note in a frightened tone that this completely debunks a widely-held theory that the species would abandon their young quickly after they were hatched.
In the third film, the alpha Velociraptor ordered her pack to hunt down the protagonists after one of them stole her eggs.
Non-action-movie version: In the 1938 Yiddish film Mamele (Little Mother), Khavkhe (Molly Picon) takes care of her whole family. A gangster, Max Katz, recruits her brother into a burglary gang, and courts her sister (with the intention of turning her into a prostitute). Khavkhe manages to pickpocket Katz's gun, and makes him write a letter breaking up with the sister. ("You may be a Katz (cat), but you'll leave here as a kitten.")
Mad Max: Fury Road: In an attempt to find redemption (and revenge), Imperator Furiosa betrays her master, Immortan Joe, and attempts to rescue his five Wives from his clutches to help them find a better life. God have mercy on anyone who tries to harm them or return them to Joe while on the way, for she will have none.
Carol Danvers aka Captain Marvel can be very nonchalant when it comes to most events but if there's one that triggers her it's the explicit threat against minors as she becomes enraged when the Skrull Talos threatens her "niece" Maria. Also in the climax when, ironically, Talos's innocent daughter and wife are taken by the Kree, Carol is distraught and goes Unstoppable Rage against her former allies. Carol also guides the Skrulls through space to a safer place. In Endgame Carol saves the teenage Peter Parker and is uncharacteristically friendly to him.
Evelyn in The Mummy Returns: Don't kidnap her son, or she'll even come back from the dead to kick your ass.
In Mother (2009), Yoon Do-joon's unnamed mother fights tooth and nail to save him from a criminal conviction.
Murder on the Orient Express (1974): Linda Arden, a.k.a Mrs. Hubbard masterminded Ratchett's murder to avenge her granddaughter, who he kidnapped and murdered, and her daughter, whose in her grief gave birth to a stillborn child which also killed her.
Mercedes from Pan's Labyrinth, considering the fact Ofelia's Ill Girl mother is too weakened from her very difficult pregnancy to really be there for her daughter. Mercedes is really the only one throughout the movie who is consistently kind to Ofelia and goes Mama Bear on Vidal:
And even better when Captain Vidal is mortally injured after having done the same to poor Ophelia, and Mercedes tells him that she'll make sure newborn child will never have memories of his evil and now dead father.
Chung-sook from Parasite despite her crimes cherishes her children and as a former Olympic hammer thrower she will mess you up if you hurt them. This is seen in the violent ending where the Ax-Crazy Geun-sae stabs her daughter Ki-jung, Chung-sook in response takes him down with the barbeque spike in revenge.
In Peppermint, An attack on Riley North's family results in both her husband and daughter's death, driving her to seek revenge, while occasionally having visions of her little girl at various points. Riley's protective streak is used against her by Diego Garcia towards the end of the film to lure her out of hiding, when he threatens to kill a homeless girl if Riley doesn't come forward.
Mi-sun from Pieta, who shows up at the beginning of the film claiming to be Kang-do's mother, is a dark take on this trope. She is incredibly protective Kang-do, willing to chew out random people who give him a hard time despite barely knowing him. She puts herself through a whole lot of grief, including being raped by Kang-do who she secretly hates, in order to get revenge for her real son who was harmed by Kang-do.
Raising Arizona: Even though she and her husband stole their "son", Edwina "Ed" McDunnough gets mighty protective of him when the evil bounty hunter comes for him.
"Give me that baby, you warthog from Hell!"
The Revenant features a literal example. Hugh Glass is hunting alone when he stumbles on a pair of bear cubs, and then he hears an angry bellow behind him. What follows is perhaps the most brutally realistic depiction of a bear attack ever put to film, and while Glass eventually wins the ensuing struggle by shooting her in the neck and stabbing her repeatedly, his injuries are macabre.
Robin Hood: Prince of Thieves: Little John's wife Fanny insists on being part of the plan to rescue prisoners from being executed by the Sheriff because one of them is their young son Wulf. Little John tries to object but Fanny and Robin overrule him.
Little John: You gone bleedin' cracked, girl? You'd get hurt! Fanny: I've given birth to eight babies, don't you talk to me about getting hurt, you big ox! Anyway, I'm not gonna just sit here and let one of 'em die, am I?
In Salt, the reason why Evelyn Salt abandoned her mission and faked the Russian Prime Minister's death was so she could save her husband. But once Orlov had her husband killed, she decides to go on a Roaring Rampage of Revenge to hunt down every other Russian agent who was involved.
A flashback in the movie Seasons of the Heart shows the main character/narrator grabbing a shotgun and charging a pack of wolves while barefoot in a nightgown to prevent them from tearing up the graves of her recently-deceased daughters.
Jasmine, the aging lioness in Secondhand Lions, might be getting old and a little bit sickly. She might not be too much to look at any more. But put one hand on her human "cub" Walter, and you are in for a world of pain, even if the strain is too much for her heart.
Twice in Seventh Son - Tom's mother reveals that she's a witch in order to fight the evil witches who are attacking her hometown and her daughter. Then Alice's mother Bony Lizzie attacks her queen Malkin when Malkin tries to kill Alice for being a traitor. Both of them die for their troubles.
Rose De Silva is willing to go to hell and back to get her mentally troubled daughter Sharon back in the film version of Silent Hill. Along the way, Rose finds that Sharon didn't have mental problems, she was all that was left of a 30 year old woman's innocence, and she was being called back to Silent Hill.
Surf Nazis Must Die has a mother avenging the death of her son against the eponymous Surf Nazis.
In Suffragette Maud evolves into a Mama Bear during the movie. At first, she just keeps her head down and tries not to get in trouble. When her husband gives her son up for adoption without her consent they have to forcibly drag her away from her son, and close to the end of the film, she rescues a fellow laundress (who is still a child) from the hellish workplace. She just walks in, takes the girl's hand and leads her to the house of a fellow suffragette, where she more or less demands that they give the girl a job. It's not only the working conditions that are awful, the boss is seen raping the girl, and is not even ashamed that Maud has witnessed it - he's implied to have raped Maud, too, when she was that age.
The Terminator: Sarah Connor. Saving the world from nuclear annihilation is considered an incidental bonus to saving her son from the machine sent back to kill him. This gets cranked up to eleven in the series.
In the 95's version of Village of the Damned, the school teacher Jill refuse to give up on her son David aka one of the creepy children and keeps protecting him no matter what. Both Jill's love for him and the death of his "twin" are the big factors in David becoming the White Sheep of the group and both mother and son's survival.
In the film Underworld: Awakening, Selene now has a daughter named Eve. Selene first meets her daughter when she is awakened by Eve when she damages her cryogenic chamber having been frozen in it for 12 years, carrying Eve to full term while sedated. Though at first Selene seems cold towards her daughter, when Eve's life is threatened by the Lycans/other vampires this mom will go to any leangth to protect her daughter. Selene is the ultimate mom fighting Lyacans, protecting her daughter, all while trying to figure out Michaels whereabouts Michael is held in the same Cryogenic lab as Selene and their daughter Eve If Selene gets punched she will think nothing of it, but if anyone touches Eve - it's their funeral.
In WarCraft, when one of the orcs threatens Draka's newborn son, she proceeds to jump on him and rip his throat out with her teeth.
One of the first break out films for the Lifetime Channel in its early years, is a movie called Not Without My Daughter. Its a film based on a true story about a woman, Betty Mahmoody, who marries a man from Iran and decides to spend her life with him in his country. She quickly discovers the harsh and brutal treatment women, especially wives, endure as part of their culture. She has a daughter with him and after she sees how the already abusive husband plans to raise her with no rights, she decides to take her daughter and escape from him back to the United States.