The Exogorth (AKA “This is no cave!”) - Star Wars
The original and probably the most iconic example: While fleeing from empire forces in an asteroid field, Luke and co. (Edit: Han actually, been a lil while since I saw this one) hide in one asteroid’s cave, but find its insides unusual and are attacked by weird creatures. As the cave seems to start collapsing they make their escape, realizing they were in the stomach of a colossal beast called an Exogorth which nearly catches them before they fly away.
The underground god/entity - The Borderlands
Basically an R-rated version of the Exogorth, this found footage horror film closes with the last two surviving main characters looking for one of their friends who has disappeared into the caverns beneath a supposedly haunted church they’ve been investigating throughout the movie. After having found evidence of pagan rituals and sacrifice in the region, it’s pretty easy to expect a demon jumpscare of some kind, but instead the suddenly damp and smelly cavern starts churning and grumbling, then closes around them as they realize only too late what’s actually going on and what’s about to happen to them. Cue the film ending as they scream and pray in agony whilst slowly being digested alive by some unseen eldritch being they were lured right into the belly of. I saw that ending just recently and I know it’s gonna stick with me for a while; it’s a very effective plot twist, but man is it gruesome and hard to watch.
The Graboid nest - Tremors 5: Bloodlines
For being one of the lesser films in the franchise and IMO the start of its decline, it does have a very effective opening scene: while two hunters are investigating unknown creature sightings in South Africa, one of them trips and falls into a massive cavern. As his friend tries to lower a rope down to him, he hears weird growling noises all around him and spots occasional flashes of movement. He then sees ancient artwork of creatures resembling Graboids eating people, and the reality dawns on him that he’s landed right in the middle of a nest. Before he can climb the rope and escape, he’s attacked and torn apart in the darkness by an Assblaster (yes, that’s its actual name) guarding the nest. The slow build leading up to the attack is very well done here, kind of a shame then the rest of the movie falls a little flat in comparison.
Ted The Caver - Creepypasta
Widely considered the very first creepypasta ever written, Ted The Caver tells the story of Ted and his friends investigating an unusual hole in the wall of a cave system they recently discovered. As they try to open the hole and explore the chamber within, the story’s entries get increasingly unsettling with mentions of bizarre sounds like scraping rock and apparently human screams emanating from within the hidden chamber. Once they finally enter it, they discover hieroglyphs implying another presence dwells within these caves, one that seems demonic in nature. Soon the cave’s paranormal activity, apparent encounters with the unseen entity and subsequent nightmares and hallucinations traumatize most of Ted’s friends out of exploring any further, but he remains undeterred. The final entry has him confidently proclaim “I will conquer this cave.” After that, the board on which the story is posted was never updated again, suggesting something horrible happened on Ted’s final journey into the mysterious cave.
God’s Mouth - Creepypasta
This one has a premise we’ve already covered so I’ll be brief: a boy and his girlfriend are exploring a cave forbidden from the public called “God’s mouth cave”, and while doing so they find themselves lost after noting the cave’s walls are unusually warm. The boy begins to panic and loses his GF in the darkness, eventually realizing the cave itself is closing around him. Just before the stalactites and stalagmites, now revealed to be teeth, start crushing him, he sees his girlfriend’s body and, quote: “screamed in agony as I watched God’s Mouth chew its latest meal.”
The Alaskan Bull Worm - SpongeBob SquarePants
We’ve covered it three times now and you’ve definitely watched this episode, so I’ll just sum it up with a quote from the scene itself:
“Ooooh…this is the tongue, and the…whole…thing is the…worm……….RUN FOR YOUR LIIIIIIIIFE!!!!”
What makes this one differ is that it’s played for laughs rather than for horror, and is done so quite effectively.
Sidenote: Honestly at this point I could’ve made a whole separate post about the “cave is alive” trope.
The railway - Coyote vs ACME
This is another more lighthearted take on the trope like SpongeBob’s, but is still done so in a way that makes it actually kinda scary, at least maybe to kids: as Kevin Avery and Paige investigate the painted tunnel Dr. Lorre hid his warning about ACME in, Wile E. continues filling out the tunnel after feeling distant rumbling and realizes with visible terror it’s none other than a railway, complete with a monstrous cartoon train that tries to chase down and crush the protagonists with metallic teeth. I appreciate this scene for taking cartoon physics usually meant just for comedy and utilizing them in a way that makes for an actually dramatic and frightening reveal, and the stakes are raised because you know the human protagonists won’t be able to just walk it off like Wile E. if they get run over.