Creatures of the Mist

The creatures of the Mist are the inhabitants of an alternate reality. After a severe rainstorm from the night before, a thick, foggy, unusual mist crept into our world, bringing the creatures with it when a top secret government experiment involving many scientists called the "Arrowhead Project", intended to peer into other dimensions, but went terribly wrong. Thus, allowing the creatures to cross over the spilled portal and into the human realm. The phenomenon first manifested in Bridgton, Maine, and spread across an unknown amount of the U.S. or possibly even the entire planet. Due to the thickness of the mist making sight almost useless to them, all the creatures in the mist hunt on the basis of scent. In the book by Stephen King, it is hinted that the mist plagued the entire world and thus the creatures nearly eliminated humanity; while in the film version, the creatures were only seen in a certain area of America and were exterminated by the military two or three days after the Arrowhead Project went wrong, preventing the mist from spreading. The creatures were presumably wiped out, making the world a safe place again for the surviving humans. And luckily preventing other parts of the world from experiencing this deadly force.

Arachni-Lobster
This 50 foot tall, lobster-like creature bisects its victims in its huge, mantis-like claws. It is known for killing Ollie during the escape from the market. Earlier in the film it may have been the creature that killed the biker, considering his body was cut in half. The Arachni-Lobster was also known for killing Private Jessup after he was stabbed three times by Mr. McVey, the store butcher, and thrown outside as a sacrifice.

Behemoth
Also known as "The Impossibly Tall Creature", the Behemoth is a huge creature with six legs. In the novella universe, other than the legs, with hundreds of Scorpion-Flies clinging to them, this creature is unseen. Although the creature's exact size is never specified, David gets the impression that its size would make a blue whale resemble a trout if both were posed together and its weight is sufficient to leave six-foot deep footprints the size of large SUVs in solid concrete. The size of the Behemoth is estimated at 240 feet tall. In the film, the Behemoth has dozens of small ray-like creatures called Scorpion Flies.

Gray Widowers
Deadly spider-like predators, each about the size of a small dog. These creatures have the ability to produce corrosive web strands which can burn through materials like cloth and flesh and fire them at prey as projectiles. In both the novella and the film, Gray Widowers normally simply kill their prey with their acidic web strands, but in the film universe, they also have the ability to capture and lay hundreds of eggs in a living human host. The eggs take about a day to hatch. They are known for killing Mike Hatlen (by spraying him in the face), Bobby Eagleton (by lassoing his leg), Myron LaFluer (by tearing his face off), Ambrose Cornell, and Stephanie Drayton. However in the novella they killed Jim Grondin, Hattie Turman, Buddy Eagleton, Mike Hatlen, and Dan Miller.

Ptero-buzzard
Nocturnal, pterodactyl-like creatures which eat Scorpion-Flies. Although Ptero-buzzards usually only eat Scorpion-Flies, they will also attack humans who get too close. One of these creatures killed a man named Tom Smalley by devouring the flesh on his neck.

Scorpion-Flies
Small, plump, flying creatures two feet long which swarm over the store windows at night. In the novella universe, these creatures have pink, burnt-flesh colored skin and their eyes are on stalks protruding from their heads. Attracted to light and the Pterobuzzards' main food source, these large flying wasp monsters have a lethal neurotoxin that causes massive swelling and suffocation within a few minutes. This neurotoxin kills Sally in the film.

Tentacles from Planet X
Squid-like tentacles that kill Norm in the storage room. The suction cups on the tentacles contain teeth which allow the suction cups to serve as mouths, consuming prey as the tentacles envelop it. It is unknown what type of creature the tentacles are attached to. When a severed tentacle is either poked or separated from the mist for too long, it decomposes into a foul-smelling liquid in a matter of seconds.

Killer Kite
A dinosaur sized, kite-like creature glimpsed flying through the mist. It only appeared in the novella universe.

Green Fly
A large, green creature which resembles a grossly misshapen dragonfly with clear wings which lands on the hood of the Scout. It only appeared in the novella universe.

Terror-pede
The terror-pede has huge, claw-like antennae with red tips, supposedly from biting into something. It was seen crawling into the store a couple seconds after the pterro-buzzards broke in the store's window.It crawled over a person and bit off his head. David Drayton was stabbing it with a torch while his son was trapped in a corner and a pterro-buzzard had him cornered.In the novella, they live in trees,while eating tentacles or tentacles eating them, preying on each other.

Other creatures
Large, spider-like creatures, each about twice the size of a full-grown man. They appear to be much larger versions of the Gray Widowers, and only their burning corpses are seen, in the film universe. In the film they were referred to by some viewers as Gspiders.

In the film universe, instead of having hundreds of Scorpion-Flies clinging to its legs, the Behemoth has dozens of small, flying creatures, about the same size as Scorpion-Flies, flying around its thorax. From what can be seen, these creature have wings which loosely resemble the fins of a ray. In the film they are referred to by some viewers as Rapiers.

Theories

 * In the film universe, the creature which attacked Norton's group was most likely an Arachni-Lobster, as the creature which attacked Norton's group was evidenced to be very large, and the biker's body was cut in half.
 * Some believe the tentacles from the loading dock to belong to the Behemoth. However, this seems unlikely, as the behemoth only has tentacles above its head and around its thorax, and even then, these tentacles are nowhere near long enough to extend more than half the length of the behemoth's legs, and it would have been heard approaching. A few fans have suggested that the tremor the grocery store experienced after the mist reached it may have been a Behemoth approaching and settling outside the loading bay, but others have discredited this (as the Behemoth's footsteps towards the end of the film were a series of brief, sharp thuds, whereas the quake the store experienced was one long, drawn-out tremor).
 * Although the creatures were exterminated in the film universe, some fans have speculated that a small handful avoided extermination and continue to roam New England.

Behind the scenes

 * The developers of Half-Life have listed The Mist as one of their primary influences for the game's plot. The first game in the series was originally going to be called Quiver, in reference to the Arrowhead military base.
 * Similar creatures also appear in From a Buick 8, also by Stephen King.
 * The Mist may have been inspired by an earlier horror story by H.F. Arnold called The Night Wire, which was published in Weird Tales in 1926.
 * In the behind-the-scenes videos for the film, its producers explain that their design approach to the creatures stressed that they were real animals, but from an alien ecology - admittedly, dangerous, wild animals, from a more brutal ecosystem we're not familiar with, but still basically just animals, made of flesh and blood. That is, they're not some kind of "demons" from literally a hell dimension.  Thus their design couldn't be too whimsical, but had to match some kind of form-follows-function logic.  For example, the Ptero-buzzard is dangerous but it isn't particularly more fantastic than a real-life pterodactyl.

Appearances

 * The Mist, by Stephen King (first appearance)
 * The Mist (2007 Film)