Alien Beast - Xenomorph, can be seen during the purge on the control room monitors stalking a female faculty worker. Generic reference: Alien. [Bet on by Bio-Med] And a creature that could be said to resemble a Facehugger from the Alien movies can be seen from the jumping out of an elevator onto a soldier. [Bet on by Bio-Med]
Alma Wade - Seen after the elevators scenes as a little girl in a white dress slowly walking towards the soldier backing away. Directly taken from the FEAR series. She possesses psychic abilities as well as space/time manipulation. No known allowances for copyright occurred, so this character should not have been allowed in the film, however the film monster stalks a crippled soldier and sings a lullaby. Specific Reference: F.E.A.R.: First Encounter Assault Recon. [Not on Betting Pool Board]
Ancient Ones - Unique godly beings partially seen at the end of the film in the pit and bursting through the earth. The driving force behind the movie. Apparently influenced by the works of H.P. Lovecraft and possibly as a not-so-subtle dig at the viewing audience.
Angry Molesting Tree - Exactly what it sounds like. Seen bursting out of elevator, more detailed scene cut from theatrical release. Specific reference: The Evil Dead. [Bet on by Wranglers]
Blob - Shapeless mass seen in a Cube Cell. Specific reference: The Blob. [Not on Betting Pool Board]
Boomer - Bloated zombie seen in a Cube Cell. Specific reference: Left 4 Dead. [Not on Betting Pool Board]
The Bride - Unknown monster listed on Betting Pool Board. Likely summoned by the wedding dress and choker. Possible reference to The Bloody Bride of 13 Curves Road. [Bet on by Digital Analysis]
The Cube Cells - A large multi-layered labyrinth of cells holding all the monsters. Generic reference: Cube
Clown - Serial-killeresque clown evoking Pennywise. The clown is shot three times with a pistol without showing any outward effect other than slight jerks when the bullets hit. This rules out a reference to a John Wayne Gacy normal human killer clown. Generic reference: It. [Bet on by Electric]
Deadites - Unknown monster listed on Betting Pool Board. Three forms of ghouls are listed on the Betting Pool Board, and at least three separate groups of undead people are shown in the movie, besides the 'main' monsters in the Zombie Redneck Torture Family, The Buckners. The three other groups are a group that spill out of one of the cells in the first wave of monsters released during the Purge. At least two in that first group are wearing blue jumpsuits. The second group is seen by Dana and Marty after the Dragonbat makes the hole in the wall for them to escape the elevator lobby during the purge. They only stand there, and so could be any generic zombies. The last group is shown on a monitor in the middle of the Purge wearing orange jumpsuits and vomiting on a technician, similar to the "Rage Zombies" in 28 Days Later and similar. Specific references: 28 Days Later... and/or The Evil Dead. [Bet on by Story Dept]
Dog Zombies/Mutants - 2 or 3 dogs can be seen when the cube is fully revealed, above Dana and Marty.
Demon - Larger horned demonic creatures, seen in backgrounds. Generic reference: Night of the Demons. [On the Betting Pool Board but not bet on]
Dismemberment Goblins - A winged creatures and possibly flightless one seen attacking a soldier in the first wave. Probably shown in the first wave of the Purge as the flying monster who tears a soldier in half with another monster.
Generic reference to imps and goblins. Generic reference: Labyrinth. [On the Betting Pool Board but not bet on]
The Doctors - Evil surgeons wearing apparent parts of faces sewn to their own. Generic reference: House on Haunted Hill. [Bet on by Accounting]
Dolls aka Babydoll Faces. Sharply dressed people wearing doll face masks, possibly summoned by matching doll face masks, Specific reference: The Strangers. [Bet on by Kitchen Staff]
Dragonbat - Large bat seen chasing people with a split vampire mouth as seen in Underworld and Blade series. Unique creation or possible reference to Underworld: Evolution or Graveyard Shift. [On the Betting Pool Board but not bet on]
Giant - Not seen in film. Generic reference: Trolljegeren. [Bet on by Zoology]
Giant Centipede - Seen in Cube reveal scene. Upper right side as one of the miscellaneous inhabitants of the Cube Cells. [Not on Betting Pool Board]
Giant Snake - Giant Cobra with a Rattlesnake's rattle. Generically referencing multiple possible movies such as: Anaconda / King Cobra. Possibly a reference to the snake creature in Season 5 of Buffy the Vampire Slayer. [Bet on by Internal Logistics]
Giant Spider - Giant spider creature seen in the Cell Cube reveal and leaping through the halls. Generic reference: Tarantula / Eight Legged Freaks. [Not on Betting Pool Board]
Gorilla (with horns) - A horned gorilla is shown in the failed attempt in Buenos Aires. Reference to King Kong or possibly Congo.
Gremlins - Generic reference: Gremlins Gremlin-looking creatures can be seen on the top right screen in the control room during the Purge for a couple of seconds at most. [Not on the Betting Pool Board]
Hell Lord aka Fornicus, Lord of Bondage and Pain - Buzzsaw face seen holding same orb that summons him. Along with the Puzzle Sphere, the monster is obviously a version of Cenobites. Specfic reference: Pinhead from Hellraiser. [Bet on by Sitterson]
The Huron - Unknown monster listed on Betting Pool Board. Described in interviews as a Native American, based on Old West settlers' fears of Indian attacks (and scalping). Generic reference: Scalps. [Bet on by Research & Development]
Jack O' Lantern - Seen on monitors during the Purge scenes. Breathing fire on top left monitor in control room during the purge. Generic reference: Pumpkinhead). [Bet on by Security]
Kiko - The Japanese floating girl ghost. Generic reference: Yurei films (ex. The Grudge & The Ring.) [Seen in Japan]
Kevin - A normal looking man that quickly dismembers people. Scenes cut from film. In interviews, Whedon describes him as looking like "some guy who works at Best Buy." Possible reference: Sin City. [On the Betting Pool Board but not bet on]
Killbot - Scorpion-like robot with buzzsaws. Generic reference: Hardware & Chopping Mall. [Not on Betting Pool Board]
Klan Members - Seen on monitor in security room right before Dana hits the purge button. Possible reference: Hunter's Blood & Twilight Zone: The Movie. [Not on Betting Pool Board]
Kraken - Massive tentacles seen in control room assault scene. Kills the Chem tech Lin. Generic reference: 20000 Leagues Under the Sea. [Not on Betting Pool Board]
Man with Plastic Bag on Head - Seen on a control room monitor suffocating an employee with a clear, plastic bag. Likely a generic serial killer parodying unique kill-tools. [Not on the Betting Pool Board]
Man in Transparent Tarp - Located in one of the cells banging a sledge hammer or axe against the walls and seen again on a control room monitor stalking somebody in a bathroom. Possible unique creation or reference to I Know What You Did Last Summer films. [Not on Betting Pool Board]
Merman - Hadley's beloved mercreature, summoned by the conch. Kills Hadley. Generic reference: Creature from the Black Lagoon. [Bet on by Hadley]
Mummy - Mummy creature seen briefly in background. Generic reference: The Mummy. [Bet on by Psychologists]
Mutants (or possibly The Reanimated/Deadites/Zombies) - Unknown if seen in film. Three forms of ghouls are listed on the Betting Pool Board, and at least three separate groups of undead people are shown in the movie, besides the 'main' monsters in the Zombie Redneck Torture Family, The Buckners. The three other groups are a group that spill out of one of the cells in the first wave of monsters released during the Purge. At least two in that first group are wearing blue jumpsuits. Part of this group is also seen just after the first wave attacks and just before the second wave. The second group is seen by Dana and Marty after the Dragonbat makes the hole in the wall for them to escape the elevator lobby during the purge. They only stand there, and so could be any generic zombies. The last group is shown on a monitor in the middle of the Purge wearing orange jumpsuits and vomiting on a technician, similar to the "Rage Zombies" in 28 Days Later and similar. Specific references: 28 Days Later... and/or The Evil Dead. If more living actual mutants: Wrong Turn / The Hills Have Eyes / The Toxic Avenger. [Bet on by Demolition].
The Possessed - Seen via monitor crawling on ceiling wearing upside-down dead faces. Possibly a reference to The Exorcist III. [Not on Betting Pool Board]
The Reanimated - Unknown monster listed on Betting Pool Board. Three forms of ghouls are listed on the Betting Pool Board, and at least three separate groups of undead people are shown in the movie, besides the 'main' monsters in the Zombie Redneck Torture Family, The Buckners. The three other groups are a group that spill out of one of the cells in the first wave of monsters released during the Purge. At least two in that first group are wearing blue jumpsuits. The second group is seen by Dana and Marty after the Dragonbat makes the hole in the wall for them to escape the elevator lobby during the purge. They only stand there, and so could be any generic zombies. The last group is shown on a monitor in the middle of the Purge wearing orange jumpsuits and vomiting on a technician, similar to the "Rage Zombies" in 28 Days Later and similar. Specific references: 28 Days Later... and/or The Evil Dead.Possible reference: Re-Animator [Bet on by Administration]
Reaver - Whedonverse monster seen during massacre. Specific reference: Firefly. [Not on Betting Pool Board]
Reptilius - Unknown monster listed on Betting Pool Board. Definitely not the above-mentioned Giant Snake. Possible reference: Reptilicus. [On the Betting Pool Board but not bet on]
Sasquatch / Wendigo / Yeti - Unknown monster listed on Betting Pool Board. Folklore references to the hairy "Bigfoot" type beast. Generic reference: Abominable. [On the Betting Pool Board but not bet on]
Scarecrow Folk - Humanoids with burlap masks and straw-based features. Attack and kill Truman the control room guard before being blown up by an apparent grenade. Generic reference: Scarecrows. [Bet on by Data Archives]
Sexy Witches - Unknown monster listed on Betting Pool Board. Generic reference: The Craft. [Bet on by Archives]
Soul Vampire - Seen ripping the soul from one of the soldiers during the first wave of monsters and on one of the monitors in the control room. Unique creation or possibly meant to be Witch or Sexy Witch (unlikely) or even a form of Vampire; all of which are on the Betting Pool Board. Otherwise reference: Shang Tsung. [Not on Betting Pool Board]
Snowman - Unknown monster listed on Betting Pool Board. Possible reference: Jack Frost. [Bet on by Communications]
Sugar Plum Fairy aka Ballerina Dentata - Unique creation summoned by the music box. Loose cross of Black Swan as a child with the tooth fairies from Hellboy II: The Golden Army. Possible reference to El laberinto del fauno. [On the Betting Pool Board but not bet on]
Tank - Huge monster seen directly below Dana and Marty in the Cube reveal. Specific reference: Left 4 Dead. [Not on Betting Pool Board]
Trenchcoat Killer - Chasing a faculty worker down the hall before throwing him to the Giant Snake. Unique creation or possible reference: Profondo rosso. [Not on Betting Pool Board]
Twins aka Grady's Daughters - Twin little girls. Specific reference: The Shining. [On the Betting Pool Board but not bet on]
Unicorn - An actual Unicorn from myth. Normally not considered a monster. Generic reference: Supernatural: Plucky Pennywhistle's Magical Menagerie (#7.14). Possibly a reference to The Abominable Dr. Phibes and what is generally considered the first "body count" film. In that film doctors are killed according to the Biblical Plagues of Egypt -one of which involved a surgeon being impaled by a brass unicorn. [Bet on by Engineering]
Vampires - Bald, gothically dressed humanoids with sharp ears. Possibly referenced earlier as Gremlins. Generic reference: Nosferatu, eine Symphonie des Grauens. [Bet on by Distribution]
Werewolf - Prominently shown. Generic reference: The Wolf Man. [Bet on by Finance]
Witch - Crying witch seen in Cube Cells reveal. Specific reference: Left 4 Dead. [Not on Betting Pool Board]
Witches - Possibly the flying witch seen stealing the soul of a soldier. Generic reference: Darkness Falls. [Bet on by Operations]
Wraiths - Various ethereal ghosts seen in initial Cube Cells and during the full reveal and during the Purge. Generic reference: 13 Ghosts. [On the Betting Pool Board but not bet on]
Zombie Redneck Torture Family aka the Buckners - Main villains summoned by reciting a Latin incantation in the diary. A family of rednecks who adhere to a religion that worships pain. Mash-Up of zombie, torture, & killer backwood family films (ex. Wrong Turn / The Hills Have Eyes). The religious element (and the family's "Black Room") reference the Cenobites from Hellraiser. [Bet on by Maintainence & Ronald the Intern]
Zombies - Three forms of ghouls are listed on the Betting Pool Board, and at least three separate groups of undead people are shown in the movie, besides the 'main' monsters in the Zombie Redneck Torture Family, The Buckners. The three other groups are a group that spill out of one of the cells in the first wave of monsters released during the Purge. At least two in that first group are wearing blue jumpsuits. Part of this group is also seen just after the first wave attacks and just before the second wave. The second group is seen by Dana and Marty after the Dragonbat makes the hole in the wall for them to escape the elevator lobby during the purge. They only stand there, and so could be any generic zombies. The last group is shown on a monitor in the middle of the Purge wearing orange jumpsuits and vomiting on a technician, similar to the "Rage Zombies" in 28 Days Later and similar. Specific references: 28 Days Later... and/or The Evil Dead. Generic reference: Night of the Living Dead. [Bet on by Chem Dept]