They consist of various monsters from mythologies (e.g., giants, e.g., cyclopes, trolls, ogres, etc., orcs, goblins, imps, undead, e.g., zombies, mummies, and vampires, etc., demons, ghouls, werewolves, werehyenas, werecats, and wererats, etc.
[6] Behemoth is an Atlantean beast that first appeared in Tales to Astonish #77 and was created by Stan Lee, Adam Austin, and Bill Everett.
[8] Blip is an electrical alien monster that first appeared in Tales to Astonish #15 and was created by Stan Lee, Jack Kirby, and Dick Ayers.
[11] Bruttu (also called the Brute That Walks) is a giant monster that first appeared in Tales of Suspense #22 and was created by Stan Lee, Jack Kirby, and Dick Ayers.
While evading the military and learning that Anne Benson secretly loved him, Bruttu made his way back to the lab and thought of himself when he reactivated the machine.
The Crawling Creature is a reptilian monster that lived in the underground parts of the Grand Canyon where it menaced a lost tribe of cave people.
[13] The Creature from the Black Bog is a giant alien monster that first appeared in Tales of Suspense #23 and was created by Stan Lee and Steve Ditko.
Sometime later, an elderly couple named John and Martha later found the Creature from the Black Bog and helped it escape from its murky prison.
Before leaving Earth upon fixing his ship, the Creature from the Black Bog rewarded John and Martha by taking their memories and sprinkling it into the Fountain of Youth which restored them to their physical age.
Dragoom is a giant fiery denizen of the Vulcan race who escaped prison from his home world and came to Earth with the intent of conquering the planet.
The computer, however, achieves independent thought and hypnotizes Poole, and forces him to build an immense robotic body, 60 feet (18 m) tall, for protection and mobility.
Calling itself Elektro and now armed with several dangerous weapons, the robot decides to conquer mankind and attacks the city of San Francisco.
Elektro takes up a job as a mail attendant in the Fantastic Four's headquarters, the Baxter Building, and later joins his fellow rehab-program creatures, the extraterrestrials Fin Fang Foom, Googam and Gorgilla, to defeat the microscopic alien conqueror Tim Boo Baa.
Gigantus is a giant monster from the underwater city of Mu who first appeared in Tales to Astonish #63 and was created by Stan Lee and Jack Kirby.
[22] Gorgilla was originally a 20 ft (6.1 m) half-man/half-ape native to the island of Borneo, who is discovered by an expedition seeking the "missing link" between man and apes.
[27] During the Monsters Unleashed storyline, Gorgilla, Fin Fang Foom, the Green Thing, and Zzutak confront Kei Kawade in the forest outside his house where they caught him offguard.
Not wanting to keep fighting Gorgolla and the rest of Monster Isle's inhabitants, Magik teleported herself, Kitty Pryde, and Bo back to the Jean Grey Institute for Higher Learning.
[34] Klagg is a giant monstrous alien with a tall head that first appeared in Tales of Suspense #21 and was created by Stan Lee and Jack Kirby.
Kraa was once a human of the Wabuzi tribe until he was mutated into a giant monster by the explosion of an atomic bomb caused by the Soviet Union soldiers.
[36] Megataur is a giant Deviant Mutate that first appeared in Fantastic Four Unlimited #4 and was created by Roy Thomas, Herb Trimpe, and Steve Montano.
[40] The Molten Man-Thing is a giant lava monster created by Stan Lee, Jack Kirby (pencils), and Steve Ditko (inker).
The Miracle Man brought the giant display of the creature to life through hypnosis so that he could steal an atomic tank from the U.S. military and fight the Fantastic Four.
[59] Rorgg is a giant alien spider monster that first appeared in Journey into Mystery #64 and was created by Stan Lee, Jack Kirby, and Dick Ayers.
[64] The Thing that Crawled by Night is a giant plant monster that first appeared in Tales of Suspense #26 and was created by Stan Lee and Jack Kirby.
Tim Boo Ba is a reptilian humanoid from the microscopic planet Devoktos, and together with an army of mercenaries he decides to conquer the Microverse.
[66] Tim Boo Ba survives and years later tricks fellow monster Googam into using the scientific equipment of Mister Fantastic to enlarge him.
[71] The Two-Headed Thing is a giant monster with two heads that first appeared in Strange Tales #95 and was created by Stan Lee, Jack Kirby, and Dick Ayers.
He led his fellow shadow monsters into invading Earth until a mystery writer named Phillip Lawrence found out and alerted the United Nations of their invasion.
[82] Attempting to get revenge on the Phantom Rider, the Mockingbird led the West Coast Avengers to the Grand Canyon where Hamilton Slade was working on an archaeological project.
This was thwarted by Hawkeye and Iron Man who managed to trap the other villains (namely Angar the Screamer, Cactus, Electro, Griffin, Hydro-Man, Klaw, Mister Hyde, Orka, Scarecrow, Titania, and Whirlwind) who were also trying to escape.