
Clockwise from top left, a Humboldt squid, an ammonite (source
◊), the Kraken and a mind flayer.

Those multi-armed creatures from the sea and the tropes relating to them.
Sub-index of Mollusk Tropes and Aquatic Animal Tropes.
Tropes
- Attack of the Monster Appendage: When monster limbs, such as cephalopod tentacles, are interacted with as isolated entities.
- Combat Tentacles: Tentacles used as Natural Weapons.
- Cthulhumanoid: Humanoids with squid for heads.
- Funnel-Mouthed Cephalopod: An octopus or squid portrayed with a nozzle-like mouth, generally based on the real creatures' syphon.
- Funny Octopus: Octopi as comic and funny creatures.
- Giant Squid: Gigantic squid as Sea Monsters.
- Knotty Tentacles: Tying up an opponent with their own tentacles.
- Kraken and Leviathan: The biggest of sea monsters, often portrayed as titanic squid or octopi.
- Naughty Tentacles: Tentacles used in less-than-wholesome activities.
- Octopoid Aliens: Aliens based on octopi or other cephalopods.
- Stealthy Cephalopod: Cephalopods, notably octopuses, are sneaky creatures akin to spies.
- Tentacle Hair: Tentacles used as hair.
- Tentacle Rope: Someone is tied up with tentacles.
- Tentacled Terror: Cephalopods, cephalopod-like creatures, and just anything with tentacles being portrayed as alien and terrifying.
- Typical Tentacle Tactics: Cephalopod enemies that use two tentacles to corral you and the others to whip at you.
- Unscaled Merfolk: Merfolk with the lower bodies of non-fish animals; octopi are a common choice.