Many people find the boneless flexibility of tentacles to be a bit unnerving, and fiction often uses this to make a scene seem creepy or otherworldly. While Combat Tentacles in action sequences are perhaps the most common example of this, suspenseful scenes can better evoke the same creepiness with the slow, serpentine, methodical movements of a Sensory Tentacle in search of hiding characters.
In science fiction, a Sensory Tentacle is often a robotic probe on a tether that's deployed by Starfish Aliens, while in horror or fantasy it's usually organic and tipped with a recognizable eye. Either way, such appendages may be multifunctional as Combat Tentacles.
Sometimes combined with Bizarre Alien Senses, depending on what form of sensation the tentacles actually detect.
See also Eye on a Stalk.
- Mezo Shoji, from My Hero Academia, has the quirk called Dupli-Arms, a set of webbed tentacles attached to his arms capable of replicating any of his body parts on the ends. These duplicates are stronger than their templates, which for sensory organs like eyes and ears makes him excellent for spying and stakeouts.
- Bob from Monsters vs. Aliens sometimes contorts his amorphous body to extend his eye on one of these, to look around corners or through openings.
- On A Bug's Life, Hopper lays his antennae on Princess Atta's face, saying that she's not the Queen, "at least you don't smell like the Queen." This piece of realistic insect behavior is not shown anywhere else in the movie, making Hopper all the creepier.
- In Skyline, each glowing probe-arm of the Hydras does double duty as a Sensor Tentacle and a head-grappling device for brain collection.
- In The Abyss, a tentacle-like construct made of animated water makes initial contact with the human explorers.
- In The War of the Worlds (1953), a viewing device attached to a long cable is inserted into the farmhouse where Professor Forrester and Sylvia van Buren are hiding. Professor Forrester knocks it down with a crowbar and escapes with it.
- In War of the Worlds (2005), a mechanical tentacle probes the basement where Ray and his daughter are hiding in advance of the aliens who are investigating the area.
- The dianoga from the garbage-compacter scene in A New Hope peeked out of the water using a single eyeball on the end of one of these.
- The giant mole in City of Ember has large tentacle-like feelers around its nose to help the creature feel its way around in the darkness. Once these feelers touch the selfish Mayor of Ember, however, it's lights out for him.
- In Monsters, the giant alien creature extends several tentacles into the service station to investigate its interior. It can apparently detect light with them, as the tentacles affix themselves to a working television as if fascinated, apparently mistaking its flickering light for bio-luminous communication from another of its kind.
- The gyrosprinter in Expedition has these sticking out on either side of its torso - they're actually extremely sensitive balance organs, like the human inner ear.
- In the Sime Gen series of novels by Jacqueline Lichtenberg and/or Jean Lorrah, the Simes were a mutated branch of humanity that could sense life energy (and often other things) via two pairs of retractable tentacles on their forearms.
- Dragons in the Dragaera novels have sensory tendrils on their cheeks and chin that detect psychic energies.
- In the Babylon 5 novel Clark's Law, the Tuchanq have ruffs of small tentacles on the back of their heads and necks that serve as their ears.
- In the John Carter of Mars series, plant-men have masses of flexible tentacles projecting from their scalps like hair, which serve as their auditory organs.
- Lilith's Brood: The Oankali aliens look like grey humanoids with anemone-like tentacles on top of their eyeless heads and in patches across their bodies. These provide their senses of sight, hearing, and taste; help them breathe; and can deliver a deadly sting.
- In an episode of The Big Bang Theory when Sheldon is home sick Leonard runs away, but he forgot his glasses back at their apartment. Howard uses a remote-controlled camera-on-a-cable to see if the coast is clear before Leonard enters.
- Remote camera-on-a-cable sensors or pole-cams are used in practically every episode of Flashpoint.
- The otyugh and neo-otyugh, filth-inhabiting monsters from Dungeons & Dragons, have three eyes located in a long, flattened stalk that can bend and twist freely, rather than in their bodies.
- BIONICLE: Kalmah gained five tentacles on the back of his head after his mutation, which allow him to sense movement in the water.
- The Tentacles from Half-Life react to loud noises. They also appear to have a small eye near the end of each appendage, but they rely considerably more on their hearing than their sight.
- Kirby: Triple Deluxe: In a variant, after Queen Sectonia merges with the Dreamstalk, she creates flowers at the end of long vines with eyes of them that she can use to see in multiple directions, as well as becoming Combat Tentacles.
- El Goonish Shive: When she has her antennae out, Grace gains a heightened sense of spatial awareness and proportion, and improved face and figure recognition. The antennae also grant telekinetic powers, which she can use to "feel" things at a distance.
- The Nozzle was used in an Overly-Long Gag on The Venture Bros., for an examination of Master Billy Quizboy. No one, not even the people using it, knew what it did.
- Æon Flux: Trevor Goodchild used a tongue/tentacle/thing to diagnose an alien (that was actually a time-traveling human) like a tricorder.
- Doctor Zin from Hanna-Barbera's Jonny Quest episode "The Robot Spy" constructed his stealth robot with two sensor plates on long tendrils, meant to analyze Doctor Quest's Ray Gun. These sensor tendrils also mind-wipe Red Shirts that discover the robot skulking about.
- Snails and slugs have simple eyes at the ends of a pair of tentacles, also known as "eyestalks".
- Tiny cameras on the end of flexible remote-guided cables are used by first responders for law enforcement or rescue work, for laparoscopic surgery, and to inspect inside engines, gearboxes, and locks without disassembling everything.
- Catfish barbels and the nasal appendages of star-nosed moles are sensory structures that detect things by feel.
- Insect antennae are sensory appendages used for touching and smelling in most species, and also "hearing" sound vibrations in some.
- Amblypygids (aka whip spiders/tailless whip scorpions/cave spiders/Nightmare Fuel) have a modified pair of legs that act as long, flexible sensory organs.
- The vampire squid possesses retractable "velar filaments" which it uses both to collect edible detritus and to detect vibrations.
- Spider webs carry the vibrations of snared prey at distances that can be dozens of times the spider's body length.
- The whiskers of some animals such as cats provide a bit of extension to the sense of touch.