One of the monsters which the Tentacles from Planet X are attached to nests near the market and uses its Tentacles to attempt to get in through the loading door. One of the Tentacles blocks up the store's generator's exhaust pipe. As a result, Jim and Myron open the loading door for Norm to get out and clear the pipe, allowing the Tentacles in.
Most of the Tentacles focus on Norm, while some of the others go for the dog food bags. When David attempts to drag Norm from the Tentacles' grip, one wards him away, allowing the Tentacles to drag Norm out into the mist, where they presumably devour him alive.
When David activates the loading door, the Tentacles withdraw back outside, but not before one is severed by the closing loading door.
When David is driving through the mist, he encounters some other Tentacles from Planet X (presumably belonging to another tentacle monster), which block the road but eventually withdraw.
The Tentacles from Planet X physically resemble those of a very large squid or octopus, but they have mouths in place of suckers which they use to consume prey as they envelop it. They also have fleshy-pink flesh on their undersides and slaty grey flesh on the rest of themselves.
In addition to the mouths and resemblance to squid tentacles, the Tentacles from Planet X also have claws lining their sides and a slit-like mouth near the tip. They also seem to be able to emit high, shrieking sounds from their mouths, retract their mouths and claws into their flesh and seem to be a shade of both grey and pink.
When a severed tentacle finally dies, it decomposes into a sizzling, black liquid in seconds.
- Some fans believe that in the film adaption, the Tentacles from Planet X are those of the Behemoth that passed over the Land Cruiser on the highway. However, this is very unlikely, as the Behemoth only has tentacles on its underside and above its head, and even then, these tentacles are not long enough to grab human victims that are at ground level like the Tentacles which killed Norm are.
- It is possible that the creatures in Stephen King's From a Buick 8 are from the same dimension as the creatures in the Mist, as, just like the Tentacles from Planet X, in our world they die and rapidly turn to a sizzling, black liquid.
- It is unknown whether the severed Tentacle turned to liquid because it was dead, or because it had been separated from the Mist for too long. However, if the creatures in From A Buick 8 are indeed from the same world as the creatures of the Mist, the latter is most likely.
- They made a cameo appearance in the DC Movie, Shazam.