Seen It a Million Times, mostly in Video Games. The danger of Combat Tentacles is cumulative. The more there are, the more trouble you're in. Named for the Sea Anemone, which although harmless to humans, is quite literally a mouth surrounded by hundreds of tentacles which snag prey and wrap it up in an inescapable web of tentacled doom. (Apparently there are examples in Eldritch Abomination which are basically just this without the Cosmic Horror aspect. Shall we move em here?)
- Star Wars Return of the Jedi: The Sarlacc, at least in the updated versions.
- Lovecraft. Most of his concoctions featured tentacles.
- The Lord of the Rings: The Watcher in the Water who attacks the Fellowship and traps them in the Mines of Moria in The Fellowship of the Ring.
- Tangle trees in the Xanth series.
- One of the monsters from Space: 1999 was a tentacled monstrosity that lured its victims into its maw by mind control and then spat out the bones.
- Dungeons & Dragons
- The 1st Edition Giant Portuguese Man-O-War was a huge version of the Real Life Earth version. Its tentacles (which could be up to 40 feet long) paralyzed its victims and drew them up into the main body to be eaten.
- The 1st edition tournament adventure C1 The Hidden Shrine of Tamoachan included a giant polyp (anemone) as one of its Mayincatec-themed dungeon's encounters. An illustration included as a player handout depicts it as looking deceptively like a dead tree.
- Call of Cthulhu campaign Shadows of Yog-Sothoth. If the Investigators fail to destroy the Watchers on Easter Island, they will be attacked by a Messenger of the Old Ones while traveling to R'lyeh. The Messenger is a giant black cloud with tendrils deployed beneath it. It uses the tendrils to grab victims and pull them up into the main mass to be eaten.
- Stormbringer Companion. The Kyrenee is a gigantic monster from another plane of existence that looks like a cloud of black tentacles floating in the air. It attacks its targets by grabbing them with the tentacles, which crushes and poisons them.
- The aquatic boss Morpheel from The Legend of Zelda: Twilight Princess resembles a large anemone (at first, anyway), and if one of its tentacles grabs Link it will swallow him, grind him a bit in its teeth, then spit him back out.
- In Ocarina of Time's infamous Water Temple, Link fights Giant Aquatic Amoeba: Morpha, a living gelatinous Combat Tentacle.
- With the exception of clownfish, this is actually what sea anemones do.. To fish, not the people.
- Jellyfish may qualify if they're large enough.
Hello, Unknown Troper. You'll need to get known to lend a hand here.