Harima takes on a Giant Enemy Crab in School Rumble in the middle of a search for cooking ingredients, and kills it offscreen with a trident. The anime exaggerated its size so that it towered over him.
Mazinger Z: Zarigan G8 was a Mechanical Beast shaped like a orange-and-red giant crab with large eyes and a long tail. It was amazingly fast and agile underwater and beat the crab out of Mazinger-Z — that had always been a lousy fighter underwater — during their battle.
In episode 4 of Tears to Tiara, the main characters accidentally call out an entire beach's worth of Giant Enemy Crabs. Since the hunting party has among their number two Badass Normal warriors, a White Mage, an Old Master cleric, and a resurrected demon king, the crabs still get slaughtered. The party celebrates with crab hot pot, using the crabs' shells as cooking pots.
Hitagi Senjogahara from Bakemonogatari starts out the series possessed by a Giant Enemy Crab. This leads Oshino to point out the real reason why Giant Enemy Crabs aren't to be messed with. They're hard to eat.
Bleach anime episode #205. At the end, all of the spiritual energy being released in the kemari game summons a giant crab-like hollow. After Uryu and Chad attack it, Ichigo kills it with a single blow.
There's also Findorr Calius, an Arrancar who is basically is a crab-man with big-ol' claws in his released mode. And considering how most Adjuchas used to look before going humanoid, he was likely a giant bony crab sometime in the past.
A filler scene in the Namek arc of Dragon Ball Z has Bulma going after a dragon ball that's gotten away from her, and ends up fighting a giant Namekian crab. Turns out the crab was just protecting her eggs.
Inverted by Vandread Jura in Vandread: not only is it a crab-mech piloted by the protagonists, but it is also primarily used for its defensive abilities.
While Magic: The Gathering does have a literal Giant Crab, it looks absolutely puny when compared to the Wormfang Crab. Yes, those are mountains it's stepping over. Suffice it to say that there are other giant crabs as well.
The first volume of Mouse Guard features a battle against several normal-sized Enemy Crabs, but since the main characters are mice...
The ruler of Atlantis in Gold Digger has a crab big enough to put an aircraft carrier on its head as a pet.
Roger Corman's immortal Attack of the Crab Monsters — People are trapped on a shrinking island by intelligent, brain-eating giant crabs. Not only were they big crabs, they could imitate people's voices.
Filipino boxer Manny Pacquiao fights one of these in Wapakman.
In the live-action ''Transformers'' films (and especially in ''Revenge of the Fallen''), Megatron's physical appearance was actually designed after that of a fiddler crab's (especially with his arms, his right arm is extremely huge and clawlike, while his left is extremely thin and bony). This even carries into his altmodes in those films: a jet-tank hybrid in the first two, and an armored truck in the third.
Larry Niven's Beowulf's Children introduces the Scribe, which resembles a giant land-dwelling horseshoe crab. Fortunately, they're also Gentle Giants...with defenses that deter all potential predators, even the grendels and the huge flesh-eating "bees" with Super Speed. To get a feel for how big they are, note that the colonists name the first Scribe they meet "Asia".
Guy N. Smith wrote a series of low-rent horror novels in which giant killer crabs scuttle amok.
Wall Around a Star has the glassy crabs grown by the Cuckoo cultists on Earth as well as found naturally on Cuckoo itself (if anything there can be described as natural).
When you're a mouse, all Crabs are Giant. Case in point: In Mossflower, the Salamandastron Quartet end up having to get past a Mama Crab that's bigger than Chibb.
In H. G. Wells' novel The Time Machine, the Time Traveler encounters some rather menacing giant crabs on his way to the end of the world.
From Harry Potter and the Goblet of Fire, Hagrid's infamous Blast-Ended Skrewts, a hybrid between Manticores and Fire-crabs. They start out as being merely a poor choice of a Care of Magical Creature class project, but fully mature they become so distinctly sinister and dangerous that they are employed for the Third Triwizards Champions task.
In John Dies at the End, a gorilla riding a giant crab (or possibly a single creature resembling a gorilla riding a giant crab) violently escapes from a chemical plant that makes drain cleaner. No, it doesn't make sense in context, that's the whole point.
There's also the memorable Crushtaceon from the novel Nuklear Age.
In The Beyonders, the first word fragment is unintentionally guarded by a giant crab. Originally it was guarded by a hermit; the crab moved in on her own. She's terrifyingly fast as well as Nigh Invulnerable, and escaping her is a chore and a half for the protagonists.
As a child, Peter Duck was marooned alone on an island with giant crabs. Returning decades later with the Swallows and Amazons, he's surprised to find that the crabs have shrunk. Or maybe his small size, isolation, and fear made them seem a lot bigger.
Chasmfiends in The Stormlight Archive are basically this crossed with giant centipedes. Many animals on Roshar also have elements of crustaceans due to Highstorms affecting their evolution.
The Doctor Who serial The Macra Terror is about a society menaced and brainwashed by creatures that look like giant crabs. Really low-production-value ones.
The Macra returned in CGI for the new series episode "Gridlock".
Intelligent crab monsters show up in the Sixth Doctor Telos Novella Shell Shock, apparently for Author Phobia reasons.
While not actual crabs, the Shadows of Babylon 5 have enormous black spaceships called Battlecrabs. Living Ships, at that, with a memorable psychic scream (not without reason) and they can cut through pretty much any other warships like soft cheese.
SCP-863 ("Patchwork Crabs"). These crabs can grow so large that they can use an entire human body as a replacement arm and use human legs to walk around on.
SCP-1527 ("Our Bellmaker, Our Radiant Skies"). SCP-1527-A are giant crustaceans with dimensions up to 1.5 meters by 2.7 meters by 2.9 meters. They have clawed hands and arms used for digging and can inflict telepathic attacks on opponents.
Crabula from Crüe Ball, who releases maggots and requires numerous hits to destroy.
The revised version for 3e uses an advanced version of the infamous That Damn Crab below. It's just as ridiculously deadly as the original.
In Return to White Plume Mountain, a group of adventurers who explore the same dungeon many years later battle the invisible zombified shell of the crab. (May generate cries of Cool but Stupid from your gamers.)
The 8 foot wide Lawful Evil Hydrax (ice elemental crab) in Basic D&D.
The Far Corners of the World brings the Monstrous Crab, better known as That Damn Crab for its tendency to grapple party members and drag them to a watery grave (assuming they somehow manage to live past the first round) as well as its insane damage output, high AC, and mindless immunity to illusions. It's listed as an appropriate encounter for 3rd level parties and is generally considered a match for 7th level parties and a total TPK machine if used as it's printed.
The monster was also reprinted with only minor tweaks in Stormwrack and given cousins of all sizes. The book also adds the Hammerclaw, which is a lobster with all the same strengths plus the ability to hide in coral/rocks and to stun the party with an at-will sonic attack for the same CR.
The first issue of Pathfinder Chronicles features a giant hermit crab that uses a giant's helmet as its shell.
The game's Bestiary features several sizes of giant crabs. Including one called a "Shark Eater".
The little-known, Aztec-themed first edition module The Lost Shrine of Tamoachan presented the characters with a talking giant hermit crab, and his Kid with the Leash, a normal-sized talking lobster. Anyone fluent in their language was likely to be able to talk their way past the two, since "talking" didn't necessarily mean "clever" in this case.
Eclipse Phase features Novacrab pod-morphs, vat-grown cyber-crabs that may be player characters. Due to the setting's ubiquitous Brain Uploading, players can select a novacrab body as well, providing a huge bonus to strength and able to survive in just about any environment.
Steel Shell Crabs are a unit for the Tritons in Monsterpocalypse. Also, the Crustaceor Lobstroyer monster.
While not strictly a Crab per se, Old One Eye and most Tyranid Monstrous creatures in Warhammer 40K can take Crushing Claws, which are described as crab-like. Being Monstrous creatures, they are quite large.
Judges Guild adventure Tegel Manor (revised and expanded, 1989). There's a giant crab creature in the Sauna that's posing as a statue. When the sauna activates, so does the creature. Not only do its pincers inflict serious damage, they can also each grab and hold up to three opponents.
RolemasterShadow World setting, supplement Kingdom of the Desert Jewel. In the Halls of the Mountain King there's a beach next to an underground river. If the PCs come within 30 feet of its lair, a giant crab will attack them and try to turn them into dinner.
Titans from the Pirates Constructible Strategy Game, introduced in its eighth expansion. Each one has four pincers that function as masts/cannons in game, and unlike the Kraken and Leviathan of the setting they can carry crew. However, they fall into Awesome, but Impractical for several reasons: They're usually ridiculously expensive, can only move with a certain facing at any one time, and without a crew they are useless as attack units and vulnerable to getting shot to pieces before having the chance to strike.
The Manas crabs in BIONICLE. Subverted, however, with Ussals, who can only be described as Giant Friendly Crabs, and the Mana-Ko, which are like Manas, only bigger and nastier, but are apparently secret agents working for the forces of good, going undercover as the guards of the Big Bad.
There was a mod for the standard headcrab in Garry's Mod that made it near-impossible to kill, screamed like Godzilla and devoured anything within seconds of it getting in range. It could be taken down with SEVENTEEN simultaneous rockets, something that could potentially crash the server.
The mud crabs in The Elder Scrolls setting are rather large for the species. Also, Oblivion includes a literal giant crab as an Easter Egg enemy, although this is a coincidence since the game came out before the Genji incident.
Semi-official word from the writers says that the Emperor Crab was resurrected to battle a massive Daedric invasion during the events of Oblivion. We never see it though, as we're stuck in Cyrodil. I suppose this would be a case of a Giant Friendly Crab though.
Morrowind's Mudcrab Merchant subverts the enemy part of the trope. It looks the same as any other mudcrab (and has the same in-game name), but instead of being hostile it is a merchant, with the most gold in the game.
One quest in Skyrim pits you against a giant Mudcrab ghost.
The boss of River Belle Path in Final Fantasy Crystal Chronicles is a nasty old crab with numerous weapons sticking out of its body from past battles. It reappears in the same position in Ring of Fates.
Cool Spot toys with this: its crabs are regular-sized, but they're quite big from the viewpoint of the player character, the spot from the logo on a 7-Up bottle.
Ecco the Dolphin has to face many Small Enemy Crabs along with the giant ones. There's actually an implied explanation for this at the end of Tides of Time; the Vortex ended up becoming the ancestors of arthropods, so it may be that these creatures hate Ecco due to species memories.
One of the units the Sai in the game Stormrise have access to is the Matriarch, a giant, genetically engineered crab that has mouths on its pincers, can spawn smaller crabs called broodlings and can shoot acid over large distances.
Cancer Bubble has also a slight subversion to him, in that, while much larger than your average crab, he's the absolute smallest of all the bosses (then again, his human half, Claude Pincer, is only in third grade).
The Mirelurks in Fallout 3 are super-mutated, bi-pedal crabs. It's worth noting that said Mirelurks have a weak point that you can hitFor Massive Damage. Mirelurk meat is also one of the better foods in the game, healing a large amount of health. Mirelurk cakes are a popular snack among wastelanders.
There's a lot of crabs in various beaches in World of Warcraft, ranging from normal sized to big to a few giant ones. Notably, in the Wrath of the Lich King expansion there is a Giant Friendly Crab as a quest-giver. Considering Blizzard's tendency to include ShoutOuts and Puns as Easter Eggs in their games, it's certainly possible this is a reference.
Monster Hunter Freedom Unite even has a mission called "the giant enemy crab".
A giant crab spawning normal-sized crabs has to be fought in the adventure game Bargon Attack.
Star Fox Command's Fichina stage has you fight against the thought-to-be-dead Andrew Oikonny, who battles you in a mech called the "Death Crab." You shoot off its legs, then its face for mass...oh forget it.
The original Star Fox has large mechanical crab enemies on Titania.
Fraxy has the Original Cancer and the Giant. Enemy. Crab.
Resident Evil 5 has you fight the U8 in an elevator shaft. Given Umbrella's penchant for using animal test subjects as B.O.W.'s, it's no wonder you'd have to fight a giant mutated crab at some point.
God Hand, at one point, features a fight between Gene and a Giant Enemy Crane (complete with pincers). Also, the entirety of the game's fourth world takes place on a Giant Robot Crab.
God Hand even makes further references to this meme: one of the Chihuahuas in the Chihuahua Races is named "Massive Damage".
Krush Kill n' Destroy had the Evolved faction, who could train giant beasts to fight for them in place of armoured tanks. One of their largest units is a giant crab with a missile launcher strapped to its back.
As well as the first and third bosses in its Enhanced Remake, Blaster Master Overdrive.
The toughest beast that Nero Chaos in Tsukihime possesses is some sort of crab spider thing that is larger than an elephant. Presumably, it's tougher than the dragon he had used before, but it doesn't matter much when your opponent kills everything in one hit regardless of anything like armor or actually damaging you.
The last level in the arcade shmup Strikers 1945 featured giant robot alien crabs as enemies.
Patapon features two crab bosses named Cioking and Ciokina. You get to cook them.
Titan Quest: Immortal Throne has regular crabs (of beach and swamp variety), and then it has the Giant Karkinos (no prizes for guessing what it is). As with the rest of the game, this has some basis in actual Classical Mythology: according to some variants of the legend, when Heracles was fighting the Hydra, Hera sent the Karkinos to attack his feet while he was otherwise occupied (wrong hero, Hera), to no avail — but on its death, she placed it in the stars as a constellation. Which means Heracles beat Cancer.
Umihara Kawase features one as the boss of field 56. It's one of the more sensemaking enemies in the game.
In Monster Rancher 2, if you send your monster on Skill (accuracy) Errantry and it makes it to the final segment, it will have to "fight" a giant crab by throwing coconuts at it. If it fails, the crab will squash your monster into a pancake.
Brave Soul gives us the Giant Enemy Fire-Breathing Crab!
X-Scape on DSiWare (made by the same company who made Star Fox Command and the director of the original Star Fox 1, both of which incidentally had Giant Enemy Crabs of their own) has a so-called "ancient" weapon called the Gigacrab, referred to in the Quest menu specifically as a giant enemy crab.
Kirby 64: The Crystal Shards features a Slightly Larger Than Average Enemy Crab as a boss battle. There's also regular-sized crabs for Kirby to munch on.
The mine boss of Wild Guns is a giant robotic crab.
One of the Bosses of Pirates The Legendofthe Black Buccaneer is a giant crab that you (As Francis Blade) can defeat using both hand grenades and the cannon that you used earlier to blow up the bars to get the trinket to turn into the Black Buccaneer.
The sixth boss of Adventure Island III is a large crab wielding an Epic Flail. The second boss of Adventure Island II is large hermit crab.
Of the very few varieties of mooks in Lost Winds, one is inexplicably a crab.
The Chryssalids of XCOM: Enemy Unknown look like huge humanoid crabs with a black carapace and two huge pincers.
Unlike the Chryssalids from the original X-COM (who were more humanoid in appearance), the remake's Chryssalids' attack is not a One-Hit Kill (except again civilians). Just like every other enemy, they must first batter down your soldiers' HP before they can be turned into zombies.
One of enemies in Cthulhu Saves the World. As their description helpfully points out, they are immune to attacking their weak spot for massive damage.
A common enemy type in the 3D games of the Tales Series. They're usually about the size of a small car.
Rather hilariously subverted in Tales of Phantasia, where you can fight an ordinary sized crab. The fact that the boss theme plays while you do so might give one the impression that it's actually dangerous, but it doesn't do anything other then run around at an absurd speed, which coupled with its sky high defense stat and tiny size, just makes it annoying for a lower leveled party to kill.
In Tales of the World: Narikiri Dungeon X, Mel and Dio can be giant ally crabs with a certain costume, that while lacking in attacks, possess the same ridiculous speed and defense as the aforementioned crab.
Pokémon has Krabby and Kingler from the very beginning, as well as giant enemy horseshoe crabs in Kabuto and Kabutops. Corphish and Crawdaunt from the third generation are giant enemy crayfish, and Anorith and Armaldo are giant enemy anomalocari. Fifth gen brings us giant enemy hermit crabs (living in giant rocks instead of seashells) via Dwebble and Crustle. Sixth gen has a giant enemy pistol shrimp, in Clauncher and Clawitzer. Of course, Pokémon runs on The Power of Friendship, so all of the above can also be Giant Friendly Crabs when you catch and train them.
Mugen Souls has this as the name of an enemy in Water World, but strangely enough, aren't very large at all — their model is only about a quarter as tall as Chou-Chou. The Crab Catchers in the same area are much larger (slightly taller than Chou-Chou).
In TERA, one of the many Big Ass Monster (or BAM; yes, that is an official name) types is a giant crab. Like other BAMs, they are not meant to be fought solo.
Burai Fighter has Giganticrab, the first boss.
The aptly named Crabahda in Phantasy Star Online 2. It's more of an annoyance then a proper threat, due to its sluggish attacks, high damage resistance outside of its weak point (Its eye), and ability to enter a defensive stance where it takes even less damage on top of concealing its weak point.
The Deah-Kani enemy type from The Wonderful 101, based somewhat on the Japanese Spider Crab. Yes, you Attack Its Weak PointFor Massive Damage, by cutting off its legs to bring it to the ground and stun it, and pry open its shell using Unite Claw in order to expose the weak point. It's the only way to do any real damage to it most of the time, even.
One of the handful of bosses in Avencast: Rise of the Mage's cavern of trials is a giant crab lacking even a weak spot; it requires environmental traps to kill.
Sonic Blast Man had a robotic one as the Level 4 enemy. This one was particularly horrifying since it could crush SBM to death with its claws even after losing them.
Chapter 15 of Realms of Ishikaze has one of these as a boss of the Ruins of Amilleo. Arashiko must attack its soft underbelly for massive damage.
In Nodwick, the party meeting a giant crab inspires them to pull out the Crab Cracker + 5, Decanter of Endless Butter and Bibs of Protection.
Fire Slicer from Axe Cop, who after eating a crab, turned into a very tall crab with super-duper sharp claws that could stab bad guys in the heart and pinch.
Karkat's guardian in Homestuck is two-and-a-half out of three. He's definitely giant and he's definitely a crab, but while Karkat does fight him, he's more of a parental figure than an enemy. Played straight, however, when crabdad dies and the comic's Mooks begin to take on his characteristics.
A much bigger and meaner version of crabdad shows up on Jake's island later in the story, filling all three points.
Cathy from "The Horrifying Experiments of Dr. Pleasant!". On one hand, she is an average sized girl. On the other hand (the other hand in this case being a giant crab claw), her claw is about 100 times larger than the average crab.
The Lattroxx race from Vexxarr, or at least the warrior drones. On the plus side, at about 10 feet in height they're not as big as some examples. On the down side...
Captain bot: Status report! Where is my welcoming team?
Exo Squad had a Neosapien E-frame design styled after crabs, which was admittedly one of the most powerful frames in the show (evident in the fact that Shiva, the best Neosapien General, preferred it to all others). Also, the crablike Neo Warriors were among the nastiest enemies the Terrans encountered.
Rampage of Beast Wars is a Transforming Mecha who chose a crab to transform into. He's also quite a bit larger than most of the other Transformers in the series and something of a sadist.
Also Rampage is near immortal and his only weak point is his spark, which Megatron has split in half so that he can keep Rampage in line by squeezing it and essentially disabling the insane robot
South Park: "Crab People! Crab People! Taste like crab, talk like people!"
My Little Pony And Friends had the Crabnasties from the episode "Fugitive Flowers". Despite a bad first impression, they turn out to be the good guys.
My Little Pony: Friendship Is Magic: "Rarity versus The GIANT CRAB!" was a meme that the bronies had a great deal of fun with after one of the creators jokingly suggested it as a Season 3 spoiler on Twitter. It's probably only a matter of time before they decide to Throw It In.
The crabs in Finding Nemo despite being normal-sized (although larger than Nemo), are actually still pretty nasty.
Waternoose, the main villain of Monsters, Inc. looks very crab-like in appearance.
The Venture Bros. season 5 episode "Venture Libre" featured a giant crab as one of Venturestein's "science-abused comrades". While non-speaking, the creature had a gender-specific name and was mourned after being killed by a punji sticks pit. Hank Venture (on a caffeine-induced power trip as 'The Bat') later eats the meat and transforms the shell into a rocket-propelled "Hank Mobile."
Haha, just kidding. Crabs like that can't exist exist in real life, right? RIGHT!?!?◊.
Holy cow! What could possibly top that◊ thing?!note Macrocheira kaempferi, the giant Japanese spider crab, which can reach sizes of up to 12' 6'' across, making it the world's largest crab. It is usually harmless to humans, but a few Japanese fishermen, who catch the crabs for food, have reported it can inflict serious injuries or even kill with its giant claws. GameFAQs and GameSpot users used that animal as an example to prove the trope naming presentation was right, Medieval Japan had giant crabs...
We're all going to be eating our words when palaeontologists find giant crab corpses in ancient Japan. It will be even worse when sword and arrow marks are found on their weak points. The official cause of death would be of massive damage.
Technically speaking, the biggest crab known to mankind is the constellation Cancer, of Western Zodiac fame, who cameos in Hercules's Twelve Labors during the hydra fight.
Other Crustaceans of Unusual Size
In addition to the giant crabs mentioned above, Magic: The Gathering also gave us the Homarids (effectively barely-anthropomorphic lobsters at war with the local merfolk when introduced), some of which were clearly a bit bigger than the others...
The collectible card/model series Pirates Of The Cursed Seas features a number of sea monsters in addition to its ships—amoung them, a handful of giant crabs.
The various deadly Lost World life forms of Fragment are distant cousins of mantis shrimp, although they've long since evolved into whole classes, possibly even phyla, of their own.
One of the bizarre inhabitants of Brian Lumley's Lovecraft-pastiche Dreamlands novels is a giant pillbug referred to as "the Running Thing". It's friendly to humans, and is a subterranean predator of various deep-dwelling nasties up to and including dholes.
Live Action Television
Countless ones in Power Rangers, though the most memorable one would be Commander Crayfish from the first season. He even comes with his own crew of Psycho Rangers.
An inversion of the "Enemy" part can be found in the Samurai Gold Ranger's Clawzord; it's a giant mech-lobster.
Monsterpocalypse the Tritons have a monster called Crustaceous which is a giant bipedal lobster.
Warcraft games have Lobstrocs/Makruras (both names seem to be used interchangeably) and the Bogstrok, which are lobster people. They're about the same size as most other humanoids, making them very large for crustaceans. There's also the truly gigantic Rokmar the Cracker as a boss encounter.
Crush Crawfish from Mega Man X3. Like his name suggests, he will crush you with those pincers for massive damage if if gets a hold of you.
Corphish and Crawdaunt from Pokémon. Anorith and Armaldo are based on ancient ancestors of arthropods, while Kabuto and Kabutops are based on the living fossil that is the Horseshoe Crab. Like the Kingler species (see above), these guys are all subversions, since you can actually recruit them as part of their team and get them to fight for you.
The Char Clawbster and Chill Clawbster in Kingdom Hearts 3D. They have a pair of propellers on their backs for flight and claws that can fire a variety of weaponry such as bombs, sleeping gas, and lasers.
A possibly dub-induced Shout-Out to this trope exists in Touhou: Subterranean Animism, where one of Reimu's options has her identifying Yamame as a "giant enemy arthropod".
The Snow Beast Recurring Boss from Dead Space 3, which is a four-legged, crab-like necromorph. Lamp Shaded, as the audio-log dealing with it states one would expect to find such a creature on a deep-sea expedidtion, rather than an ice world. Makes more sense when you find the log showing that Tau Volantis was a water world before its inhabitants froze it over.
Injustice: Gods Among Us Aquaman aids the heroes in rescuing Batman in Stryker Island, by summoning an army of giant lobsters to distract the Regime. Being King of the Seas doesn't seems so lame now does it.
Giant marine cousins of the pillbugs (a.k.a. rolly-pollies, sowbugs, woodlice) you can probably find eating rotted plant matter in your compost heap are quite common around deep-sea hydrothermal vents.
Lobsters. While people are probably most used to 1—2 pound lobsters (i.e. the kind you eat) those are around 7 years old and nowhere near as big as lobsters get. A very long-lived lobster is also a very large lobster, with a length of over 4 feet and a weight of over 30 pounds.
Barnacles are usually no more than an inch or so across, but one variety that lives symbiotically on the flukes and jaws of humpback whales can grow to the size of a plate. The whales carry their barnacles into swarms of plankton which both species consume, so they eat much better than sessile barnacles do.