The Gigantic Mechaniloid CF-0 is the boss of the opening stage from Mega Man X2, a giant Mechaniloid that has great power, but low speed due to its size and weight. The X-Hunters gave orders to mass-produce CF-0 and use them as an army to conquer cities around the world. The Maverick Hunters discovered that the abandoned factory the CF-0s were being manufactured in was being used by Mavericks and attacked the factory. Several inactive CF-0s can be seen in the factory, but only one was complete at the time, which fights against X.

CF-0 walks and jumps around the room, sometimes attacking X with punches. The only parts that cause damage to X are the head, arms and feet, being possible to pass through his body without receiving damage. CF-0 can only be damaged by attacking the head.

Wire Sponge, known in Japan as Wire Hetimarl is a sponge-type Maverick from Mega Man X2. Created in one of Sigma's Maverick producing factories, an accident resulted in him having a personality disorder, which causes him to be childish and easily amused. Yet, he still had impressive combat abilities and was placed in charge of the Weather Control Station, where he found delight in passing the time by playing with the weather system.

He also appears as a boss on Mega Man Xtreme 2, and makes a cameo appearance in Mega Man ZX Advent, absorbed into the base of the Tower of Verdure, Rospark the Floweroid's stage.

Wheel Gator, known as Wheel Alligates in Japan, is a Reploid from the Mega Man X series modeled after an alligator.

He was an officer serving in the Maverick Hunters' 6th Naval Unit along with Bubble Crab (the two did not get along). Due to his ferocious nature, Gator attacked a fellow Hunter during a mission and was later hunted as a traitor. To satisfy his destructive impulses, he joined Sigma's Maverick army and was given control of a massive dinosaur-modeled tank, which he tried to use to raze an entire city in Mega Man X2.

Bubble Crab, known in Japan as Bubbly Crablos is a crab-based Maverick from Mega Man X2. He was once a Maverick Hunter and served in the 6th Naval Unit along with Wheel Gator (the two had a strained working relationship and always argued, which could explain Bubble Crab's weakness against Spin Wheel). Being extremely avaricious, Bubble's only motivation in life was to amass great wealth, joining Sigma's rebellion seeing it as his big break. He was put in charge of transportation, and tasked with defending the Mavericks' deep-sea submarine base.

Flame Stag, known in Japan as Flame Stagger is a Reploid in the Mega Man X series based off a deer. Once serving as a member of the Maverick Hunters 17th Elite Unit, he followed along with his friend Boomer Kuwanger to join Sigma's first Maverick rebellion. Afterwards, his whereabouts became unknown, but later he resurfaced occupying an active volcano with the intent of triggering an eruption that would block out the sun with volcanic ash, starting a new ice age.

Morph Moth, known in Japan as Metamor Mothmeanos is a Maverick in Mega Man X2 who is based off a bagworm moth. An unusualReploid of unknown background, he has the ability to transform/evolve his body by absorbing scrap from other Reploids, robots, and machinery. Under Sigma's orders he occupied the Robot Junkyard, using the scrap materials there to resurrect fallen Reploids. When the player first meets him, he looks like a strange dangling organism with eyes, which is actually a larva/cocoon. He can move around and drop junk on the player, and even do a spiraling attack with it. His weakness is Speed Burner.

Magna Centipede, known in Japan as Magne Hyakulegger is a centipede-likeReploid in the video game Mega Man X2. He is a former Maverick Hunter of the 0th Special Unit that was captured by Sigma's forces during a mission and brainwashed. Now a Maverick, Magna Centipede was stationed at a computer center, where he began transmitting the Maverick Virus around the world. X fought against Magna Centipede in the computer center and destroyed him.

Magna Centipede also appears in the Game Boy game Mega Man Xtreme as a reproduced boss data after completing the game once, in the Boss Attack mode from Mega Man Xtreme 2, and as one of Metal Shark Player's attacks in Mega Man X6.

Crystal Snail, known in Japan as Crystar Mymine is a snail-type Maverick in Mega Man X2. His origins and motives are a mystery; regardless he guards the Energen Crystal mine under Sigma's command.

Overdrive Ostrich, known in Japan as Sonic Ostreague is an ostrich-typeMaverick in Mega Man X2. Overdrive was once a Maverick Hunter of the 7th Airborne Unit, but retired after an accident that cost him the ability to fly. Sigma later sought to recruit him, seeing use for his superior speed. Overdrive, sensing appreciation for his abilities, pledged his loyalty to Sigma and was stationed at an abandoned missile base; charged with the task of launching the one remaining missile stored there at the Hunter Base. Before confronting Overdrive, X manages to destroy this missile just as it launches.

Violen is one of the X-Hunters from Mega Man X2. Not an intellectual in any sense of the word, his rowdy and aggressive behaviors characterize him as the brute force of the organization.

Serges, known as Sagesse in Japan, is one of the X-Hunters of Mega Man X2. A brilliant Reploid scientist, his vast intellect makes him an integral part of the organization. It seems that he came up with the Unification Project, a plan to resurrect Zero and use him for their own purposes.

Agile is one of the three X-Hunters in Mega Man X2. He is characterized by his fast movement and expertly wielded beam-sword, and (in the Japanese version) his polite speech pattern and reserved personality. His role in the organization seems to be that of a military strategist, formulating plans and organizing operations.

Sigma formerly referred to as "Commander Sigma", is the main antagonist of the Mega Man X series. He serves as the final boss in all X series games except Mega Man X: Command Mission (where he makes no appearances) andMega Man X8 (appearing as the final boss if the game is played on easy, and as the penultimate boss if the game is set to normal or hard difficulty, since Lumine is fought on normal or hard).

The first Reploid created by Dr. Cain,[1] Sigma was considered the finest of the Reploids and was the first leader of the Maverick Hunters; peace-keeping Reploids who defend humans against their renegade counterparts. Although he was once honorable, Sigma unexpectedly goes Maverick in the beginning of Mega Man X and rebels against humankind. He defects to the Mavericks and assumes the role of their leader. Under Sigma's command, the Mavericks grow into a legion dedicated to the extermination of the human race. Sigma instigates many of the destructive Maverick Wars, with the Maverick Hunters existing to crush Sigma and his minions.

Although he has been destroyed countless times, Sigma's programming always survives and builds himself a new form, ready to menace the world once again.[2] It is implied that he grows more insidious and vengeful with each transformation, with each successive plan becoming more and more desperate and aggressive. His primary enemies are X, Zero, and more recently, Axl.

Wheel Gator – Strike Chain (Shoryuken when he raises into the air to spin at you)

Overdrive Ostrich – Cystal Hunter (Get low and Shoryuken when he jumps into the air)

Crystal Snail – Magnet Mine (Force him out of his shell with Magnet Mine, then Shoryuken when he jumps)

Magna Centipede – Silk Shot (Shoryuken when he's on the ceiling)

Flame Stag – Bubble Splash (Shoryuken when he's jumping around)

Bubble Crab – Spin Wheel (Jump to lure him into jumping after you, then Shoryuken)

Wire Sponge – Sonic Slicer (Shoryuken when he's hanging from the ceiling)

Morph Moth – Speed Burner (Shoryuken when he's hanging there, then when he's flying)

Zero is one of the three main characters of theMega Man X series, the main protagonist of the Mega Man Zero series, and an important supporting character in theMega Man ZX series as the Biometal Model Z. He is the successor of Bass and the greatest creation of Doctor Albert W. Wily. A high ranking Maverick Hunter in the X series, and a legendary freedom fighter in the Zero series, he's a die hard warrior who doesn't hesitate to take action. However, behind his cold and emotionless attitude lies a wounded soul.

Sigma's advanced circuitry seems to do its job, as he seemingly remains stable for months after the lab incident. He gradually succumbs to the virus inside of him and grows more volatile. Without warning, he leads a mass revolt among the Reploids, declaring total war on humanity, which is seen depicted in The Day of Σ.[4] Many Maverick Hunters follow Sigma out of loyalty, leaving Zero, who by this time was reformed and had become a powerful Maverick Hunter, in charge of the organization. Mega Man X, the last creation of Dr. Light and the base model for every Reploid, decides to join Zero as thanks for saving his life. X and Zero battle through the Maverick regime, and it is X who finally destroys Sigma, who laments X's decision for siding with humanity, feeling that Reploids would have prospered without humanity holding them back.[5] But, though his physical body is scrapped, Sigma's "soul" (the Virus) survives. After the end credits roll, Sigma's face appears on a blue monitor and warns X that he will be back.[6]

The Sigma Virus also officially referred to as the true form of the 'Suffering Circuit' in Mega Man Zero Official Complete Works, is Sigma's true form, first seen in Mega Man X2. It is formerly known as the Maverick Virusthat turns Reploids and even Maverick Hunters into Mavericks.