The mutant operatives and mechanical beasts deployed by Satan Egos to plunge the world into chaos.

The very first monster created by Egos. Disguised as a woman with a red umbrella, she was ordered by Egos to assassinate high-ranking police officers. This was accomplished using her umbrella, which concealed a hidden needle tipped with acid that caused a sudden, fatal heart attack upon injection.

She also killed an FBI official named Special Agent Bosner, who spotted her before entering Tokyo International Airport. Her true form is Man Bat, a descendant of the ancient Zapotec culture. His main weapon is a large scythe.
Episode 1

Fang Lion Monster can manipulate people's thoughts by making them believe their darkest wishes will come true. If a person wishes for someone to die, Fang Lion grants that wish by making the assassination look like a suicide or by disposing of the victim's body entirely.

His main weapon is a spear.
Episode 2

Ordered by Egos to hunt down the informant who had been revealing the society's secrets to Battle Fever, Death Mask Monster carried out her mission by disguising herself as a human.

She also attempted to steal the blueprints for Battle Fever's top-secret giant robot, but the blueprints provided by Battle Japan were fakes. Battle Fever ultimately defeated her at a scrap yard. Her main weapons are a cutlass sword and exploding daggers.
Episode 3

Originally a human psychic named Bengal Tiger, he completed his psychic training in India. He possesses powerful telekinesis and the ability to take physical photographs of spirits and memories. After swearing allegiance to Egos, he was transformed into the Psychokinesis Monster.

He can revert to his human form to mislead the public into thinking he is a normal psychic. Ordered to use his mind-reading abilities to learn about Battle Fever's top-secret weapon, he tracked down a woman friendly with the team and photographed her memories, successfully obtaining images of the blueprints.

However, Battle Fever intercepted and destroyed him before he could deliver the photos to Egos.
Episode 4

Buffalo Monster's mission was to hunt down a resigned defense department official whose family had been abducted by Egos. In exchange for his family's safety, the official was forced to confirm when the Battle Fever Robo was finished.

Buffalo Monster was the very first Egos Monster to have a giant robot version of himself, named Buffalo Robot, whom the monster affectionately referred to as his "younger brother." He wields a large cutlass sword, and his horns can be thrown as boomerangs.
Episode 5

Disguised as an ordinary shrine, Doguu Monster was carried directly into a military airbase facility. It then revealed itself to be alive and attacked the base personnel by vaporizing them.

Commander Hedder and the Cutmen took over the base to create confusion regarding Battle Fever's Shark Ship, though the team eventually discovered the takeover. Doguu Monster has glowing red eyes and carries a large double-edged sword.
Episode 6

Fireball Monster led a group of Cutmen to perform widespread acts of arson. His ideology is that those who refuse to join Egos do not deserve the right to live. He assigned Cutmen disguised as humans to burn the homes of these refusers.

Their plans backfired when a young boy recovering in the hospital began having visions proving Egos was responsible for the fires. Fireball Monster uses a three-pointed sword. His giant robot counterpart resembles him perfectly but features a sword that shoots flames.
Episode 7

Assigned by Egos to distract children with sports rather than their desired life goals, Sports Monster hoped to manipulate the population of Japan into becoming lazy and complacent.

He wears a hockey mask and carries a hockey stick as a deadly weapon.
Episode 8

A cold-based Egos Monster connected to the "woman from the land of ice" incident. Icicle Monster can disguise herself as a human, unleash freezing attacks, and battle with an Icicle Spear.
Episode 9

An elephant-themed Egos Monster modeled after the ancient Naumann elephant. He can disguise himself as a human and fights with sharp tusks and a tomahawk. His giant robot counterpart, Nauman Robot, carries similar weapons.
Episode 10

A cobra-themed Egos Monster deployed during a major pet kidnapping case. He fights with a whip and a pair of cobra bodies, while his giant robot counterpart uses similar cobra weapons along with rock bombs and a scimitar.
Episode 11

A rose-themed Egos Monster tied to a cursed killing technique known as the Rose Snowstorm. Her elegant appearance hides a deadly fighting style built around beauty, deception, and floral attacks.
Episode 12

An egg-themed Egos Monster involved in a scheme surrounding mysterious golden eggs. His strange motif reflects Egos' ability to transform almost any object or idea into one of Satan Egos' monstrous children.
Episode 13

A space-themed Egos Monster whose design evokes stars, planets, and cosmic energy. He appears in a case centered around beauty, obsession, and the monstrous ambitions of the Secret Society Egos.
Episode 14

A snail-themed Egos Monster connected to one of Egos' bizarre food-related plots. His shell-like armor and sluggish motif disguise the danger of his attacks and the cruelty of Egos' experiments.
Episode 15

A martial-arts-themed Egos Monster built around close-quarters fighting. He serves as the central threat in a combat-focused incident involving the "Queen of Darkness."
Episode 16

An Egos Monster associated with the theft of the Monster Machine. His appearance and name suggest a body marked by exposed blue veins, giving him a grotesque organic design among Satan Egos' creations.
Episode 17

A magnet-themed Egos Monster whose powers center on magnetic force. He is connected to a plot involving birds being drawn toward Egos' base, using attraction and control as part of the society's scheme.
Episode 18