Shark Fin of Doom

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"Our dorsal fins are sticking out! I wonder how many times that's screwed things up?"

— Shark, The Far Side

The Threatening Shark doesn't need to show itself in full; the shark's dorsal fin sticking above the water is an iconic image in itself.

This can be subverted when a character falls in the water, sees a fin (or many fins) sticking out of the water and promptly imagines, "Oh, Crap!, a shark! Gotta beat it!" However, most of the time it's just someone pulling a prank by swimming under the water with a fake shark fin strapped to their head or back. Or it may be a Friendly, Playful Dolphin. This, in turn, may end up a Double Subversion when the characters don't fall for it, but then it turns out to be a REAL shark. Or, more comedically, a Devious Dolphin. While orcas are technically dolphins, they are seen as far more dangerous and likely to be portrayed this way in a serious manner. Savage Spinosaurs can also apply this trope, with its aquatic habitat and large sail on its back.

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Examples:

Advertising

• Effectively subverted in this ad called "Rethink the Shark", from a campaign aimed to put deadly shark attacks into perspective.

Anime & Manga

• JoJo's Bizarre Adventure Golden Wind has the Stand named Clash, which takes the form of a metallic shark. It can teleport between and dive into any open liquids, no matter how small or shallow, and in certain scenes where it appears its dorsal fin is the only thing visible, poking out of things like a soup bowl, puddles of water, and even the tears rolling down someone's cheek.
• Played with in Negima! Magister Negi Magi when the class takes a trip to an island. Negi is put 'in danger' so Asuna will make up with him after a falling out. The 'sharks' turn out to be Ku Fei and Natsumi in diguise.
• Arlong from One Piece, who is a shark fishman, does this during his battle with Luffy.
  • Later in the series, Hody Jones weaponizes his dorsal fin by putting a blade over it to slice through things as he swims.

Film — Animated

• Literal inversion in The Good Dinosaur. When the pterosaurs make their second appearance, their mouths are seen first, sticking out of the clouds, evoking this trope turned upside-down.

Film — Live-Action

• Airplane! in a Stock Parody of Jaws had the tailfin of the airliner slicing through the clouds.
• The Black Demon: Inés watches through binoculars as a gigantic fin (belonging to a megalodon) advances towards the boat that brought her and her children to the offshore rig that her husband went to inspect. It disappears for a second and then the Black Demon attacks the boat, leaving everyone stranded on the rig.
• Deep Blue Sea: The sharks' dorsal fins breaking the water surface is sporadically used to betray their presence. However, this is played with in one scene. Susan is wading through a partially submerged corridor to retrieve the MacGuffin from her laboratory when a shark seems to approach her from behind, but it turns out to just be a harmless shark model. Then seconds later, she sees a second fin, which turns out to be the real deal.
• In Godzilla (2014), in scenes where the titular monster is swimming, only his dorsal spikes are visible above water, creating an effect similar to this trope.
• In Great White, the major Oh, Crap! moment occurs when, after paddling through the night in the slowly deflating life raft, Michelle finally sees the shore in front of her. Turning to tell Charlie and Kaz, and then lets out a soft "Oh fuck" as sees two shark fins rapidly approaching the raft from behind.
• Jaws
  • While the armed men are patrolling the beach watching for the shark, a fin appears in the water, and people panic and flee the water. When the men in the boats approach the fin, it turns out to be kids with a fake fin pretending to be a shark.
  • At other times in the movie, the real shark's presence is revealed by its fin appearing, such as when it attacks the boats in the estuary/pond and while Brody, Hooper and Quint are out on the ocean hunting it.
• The Jurassic Park films have a variation with the neural spine sail of Savage Spinosaurs.
  • In Jurassic Park III we see the Spinosaurus's massive dorsal sail jutting out of the water before it attacks the protagonists.
  • Jurassic World Dominion. Our heroes are escaping in an underground tube train when the Big Bad turns off the power, forcing them to continue on foot through an abandoned amber mine. Part of the mine is flooded and we see the spine sail of a swimming Dimetrodon moving through the water in their direction, though it catches up on land.
• The Meg:
  • As usual for shark movies. Megalodon's especially large fin provides the main characters an easy way to track the gigantic shark from the surface, as well as a Mass "Oh, Crap!" moment when it goes below the water...
  • More humorously, when Meiying is playing by herself, she walks past a roomba floor cleaner that someone on the research station seems to have provided with a mini shark fin as a joke.
• In A Nightmare on Elm Street 4: The Dream Master, Freddy does this in Kristen's beach nightmare, with his glove taking the place of a shark fin.
• In Open Water, the first signs that things are going to get really bad for the couple that's been left behind by their diving boat is the brief shot of a shark fin.
• Subverted in Percy Jackson and the Sea of Monsters, when Percy, Annabeth and Tyson are stuck in a small lifeboat, and start seeing what appears to be shark fins, circling around. They soon find out they AREN'T shark fins at all: They're Charybdis's teeth.

Literature

• Camp Haunted Hills: Subverted when Stuart first dives into Misty Lake and sees a fin heading towards him - it turns out to be Flipper, the swimming counselor's assistant, with a fake fin on his back.
• In a Nancy Drew Files book, as Nancy escapes from the boat where she and her friends are being held captive, intending to swim to shore for help, the first sign of serious trouble is a shark fin gliding through the water. She forces herself to get over her fear and swim to shore as fast as she can.

Live-Action TV

• The Boys (2019). In "Over The Hill With The Swords Of A Thousand Men", the Boys have a Mass "Oh, Crap!" when shark fins start slicing through the ocean towards their motor yacht like wire-guided torpedoes, trying to ram it below the waterline. This is their first indication that The Deep is on the scene.
• The Brittas Empire: In "Mr Brittas Falls In Love", a mix-up involving a dolphin leads to a shark being put into the pool. Most of the shots we get of it is just its fin as it tries to attack anyone who gets in the pool, with the only time we see any more of it being its face as it almost attacks Helen.
• The Doctor Who Christmas Episode "A Christmas Carol" has one scene where a flying shark maneuvers through fog, and its fin is the only visible part of it.
• One of the stories on the I Survived episode that focused on Hurricane Sandy was of a man swept out to sea from his home. He realized how dire his situation was upon seeing a fin pass by him.
  "I didn't know if it was a shark or a dolphin and I wasn't going to wait to find out.'
• The Lord of the Rings: The Rings of Power: The Sea Serpent makes its first appearance by sticking its dorsal out of the water. He rapidly approaches the raft full of people he shipwrecked earlier and kills almost everyone. Several shots of the monster show him resembling a goblin shark.

Magazines

• MAD Magazine had a feature that played with this. Among other things, it showed a shark with a sinister look on his face approaching a beach while "hiding" his fin under an old box, a shark near a large city beach with graffiti on the fin, and another with a brave guy diving off a boat to hunt the shark with the tiny fin. Once he's underwater, he's greeted by a HUGE shark who, apparently purposely kept only the very tip of his fin above the surface.

Newspaper Comics

• One of Calvin's hilariously morbid snow sculptures in Calvin and Hobbes involved a snowman being chased by a pack of sharks portrayed as fins protruding up from the snow.
  Hobbes: Snow sharks?
  Calvin: That guy's a goner.
• The Far Side: Along with the page-quote example, another strip has a cowboy on a cattle drive noticing a "cattle shark" fin among the cows.
• In Sherman's Lagoon, Sherman, an actual shark, does this occasionally. His crab friend does it for kicks to scare the hairless beach apes.

Tabletop Games

• In Dungeons & Dragons, the distinctive dorsal ridge of the bulette can sometimes be seen sticking out of the ground as it digs its way towards its prey. This is one of the reasons the bulette is sometimes called a "land shark".

Video Games

• Andro Dunos 2 has a Leviathan mech who appears firstly as a Boss Tease, being a set of gigantic fins above the water. It then assaults you with projectiles, and after fending off it's attacks the Leviathan submerges it's fins, with you taking a dive to follow it for an inevitable boss battle.
• In Animal Crossing, sharks can be distinguished from other fish by their fins above the water, but sunfish and suckerfish do it as well.
• Illusion of Gaia has a scene with Will and Kara stranded on a raft and encircled by shark fins. But after a few moments of panic, the sharks just leave, leading to an Anvilicious conversation about how only humans kill things when they're not hungry.
• Gyorgs in The Legend of Zelda: The Wind Waker first appear this way, before they try to ram your ship.
• Luigi's Mansion 3: Captain Fishook, the Boss Ghost of Floor 12, approaches the pirate ship with only his fin showing until the dramatic reveal.
• Mario & Luigi: Superstar Saga: The beach has a pair of enemies that play with this. One is a skeleton land shark. The other is just a cheep-cheep wearing a large fin. Together they attempt a Shell Game to mess with the player.
• Mega Man Battle Network 6: Cybeast Gregar and Cybeast Falzar: In DiveMan.EXE's scenario, in the aquarium's computer, there are security systems in form of shark fins that will wander around, either trying to get you or just patrolling certain areas.
• Subverted in Power Rangers Lightspeed Rescue. The level near a waterfront sees plenty of shark fins sticking out the water beyond a pier, but since it's impossible to fall in they just serve as Monstrous Scenery.
• Ratchet & Clank: It's been a staple of the series since the beginning to mark dangerous bodies of water with circling shark fins. If Ratchet falls into one and doesn't get back to dry land within three jumps, the shark will eat him.
• Secret Agent: Some water pools have sharks in them, shown as a shark fin. However, since the protagonist has Super Drowning Skills anyway, the sharks are just for show.
• These are a standard enemy in ToeJam & Earl. Opening the Earthling present while surrounded by water will always result in one, sine they're the only enemy to appear in water. Frustratingly, there's a Game Genie code that grants immunity to most damage ^note anything that makes the character say "youch!" — the only dangers that don't are being Squashed Flat or hit with tomatoes, but if you're hit in or near water while using said cheat, the game crashes, making sharks very dangerous indeed.
• The World Ends with You: Shark Noise can use their fins as a slashing weapon while submerged. So, in this case, the shark fin is the doom.

Webcomics

• It's Jeff! has had this happen to baby land shark Jeff on a few occasions. By the time he goes to the beach he's taken to disguising himself as a dolphin just to avoid it.
• Parodied in this strip from Mr Lovenstein.

Western Animation

• Arthur
  • Subverted in the theme song. Brain sees what appears to be a brown shark fin in the swimming pool, his reaction startling Muffy. It turns out to be Mr. Ratburn's nose.
  • Subverted twice in an episode that takes place at the beach. Sue Ellen spots what she thinks is a shark, but it turns out to just be Mr. Ratburn doing the backstroke just like in the theme song. She sees another fin and panics, thinking it's a real shark this time. It's a dolphin.
• Big City Greens: The episode “Shark Objects” is about Cricket trying to pull this prank on beach-goers, and although Nancy is supposed to be stopping him, she can’t help but encourage it. In the end, it goes too far when the lifeguard tries to harpoon the “shark,” and it’s up to Nancy to try to stop him.
• In the classic Disney short "No Sail", Donald Duck and Goofy are stranded on a boat and shark fins start circling them. Goofy lifts one fin and finds nothing underneath. Donald tries the same, but comes face to face with a real shark.
• Subverted in Garfield in Paradise — Garfield panics when he sees what looks like a shark fin while he's floating on the water, but it just turns out to be Odie with his ears arranged to look like a shark's fin.
• In one Humphrey the Bear cartoon, Humphrey takes the keel from a toy sailboat and wears it on his head as a fin to scare away fishermen and keep the fish for himself.
• Lilo & Stitch: The Series: In "Sinker", the titular experiment is mostly seen as a fin sticking above water as it's an aquatic experiment with a small body and a large and incredibly sharp dorsal fin meant for slicing watercraft in half.
• Looney Tunes:
  • In an early short, Porky Pig and his cat are out fishing when a flying fish decides to have some fun and sticks its side fin out to look like a shark's fin. The cat catches on and grabs the fin, but that time the shark was real.
  • In the Bugs Bunny cartoon "Wet Hare", villain Black Jacques Shellaque sees a fin on a stream and figures it's one of Bugs' tricks. He dives in to get Bugs, but finds an actual shark instead.
  • Another Looney Tunes short, Porky's Naughty Nephew, has Porky's nephew Pinky using a toy sailboat to simulate a shark fin during a swimming race, which scares Porky into swimming fast and winning the race. When Pinky tells Porky that the fin was fake, Pinky lifts it up to reveal a real shark, sending both fleeing.
• My Little Pony: Friendship Is Magic: An intentional subversion in the Cold Open of "Leap Of Faith": it's actually Big Mac, of all ponies, giving Apple Bloom a scare right after she's asked if she'll ever be scared of the water in response to Granny Smith telling how she engaged in dangerous High-Dive Hijinks in her youth.
• Rocket Power: Done by the main characters because of the overcrowding at the beach. However, this backfires when they are not permitted at the beach. They end the ruse by attaching the shark fin on a plank of wood at sea, which is discovered by officials.
• In the Roger Rabbit short Trail Mix-Up, Roger ends up in a lake and is scared away upon seeing a shark fin. It's then revealed to be Droopy, who quips "Gets him every time."
• The Simpsons:
  • Done in "Itchy And Scratchy Land" by Homer when the family is at the beach. Homer wears a fin attached to his back, causing the beachgoers to run away. Then when Bart swims up right next to him doing the exact same thing, Homer screams, "AHHHH! Sharkboy!" and runs away.
  • Played With in another Simpsons episode, a Treehouse of Horror story titled "Night of the Dolphin" about killer dolphins. Lenny is out for a night swim and gets surrounded by fins. He's scared that they're sharks, "the assassins of the sea", but they're just friendly dolphins, "the clowns of the sea" — who proceed to kill him.
• Total Drama:
  • The cliff-jumping challenge in "Not So Happy Campers - Part 2" is made even worse by the presence of sharks, which swim around with their fins as clearly as threateningly visible above the water.
  • While wrestling in a secondhand ball pit in "Million Dollar Babies", Duncan spots a shark fin poking out from the surface and panics. Courtney is skeptical and picks it up, revealing that the supposed shark fin is just a semi-hardened loose flap of a dirty diaper. She mocks Duncan for being scared by the "big bad diaper shark".
• Total DramaRama: During her time as a lifeguard in "MacArthur Park", MacArthur has to deal with a fake emergency regarding Izzy. She spots the girl being pursued by a shark, as evidenced by the fin sticking out above the water, and tries to warn her. Izzy then reveals it's just her cat who enjoys to swim underwater and goes faster with a fake dorsal fin tied to its back.

Real Life

• Despite its prevalence, this trope rarely appears in real life. Most sharks ambush their prey by coming from beneath them, even in shallow water. So whilst a fin may tip you off that a shark is around, it's probably just the shark inspecting you. It's when you can't see it any more that you need to start worrying.
• This photo went around the world like mad a while back. It's really a surfer and a dolphin, but that's not why it was popular.
• In the Tommy Bartlett Water Show at Wisconsin Dells, they have (or at least used to have years ago) a scene where a "shark" approaches the performers, represented by a shark fin floating on a piece of wood which is towed by fishing line towards the performers.
• Any aspiring Troll can find these in strap-on form in your local superstore for all your pranking needs.
• When Australia II won the America's Cup from the New York Yacht Club for the first time in 132 years, a spoof Jaws poster was made showing its famous winged keel piercing the water and a tagline, ''Just when the New York Yacht Club thought it was safe to go back to the water..."

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