Shadow Man is a stealthy and powerful ninja-themed Robot Master that first appeared in Mega Man 3. Possibly alien in origin, Shadow Man was originally an unknown, deactivated robot discovered by Dr. Wily, who remodeled and reprogrammed him. The metal body of Shadow Man does not match any material found on Earth. He is a master of ninjutsu, and can summon a giant frog robot to ride on or small frogs to check areas for him (a reference to Jiraiya, a rogue ninja hero from a Japanese folktale, who mastered frog magic). Shadow Man's main weapon is the Shadow Blade, a large shuriken coated with a deadly liquid.

Spark Man is a Robot Master from Mega Man 3 created by Dr. Light and Dr. Wily. He was originally created to charge electricity before Dr. Wily modified him to be a combat robot. Spark Man is designed after a spark plug, and does not have hands. In place of them are two high-voltage electrodes, capable of producing powerful electric shocks and firing off balls of pure electric energy, also known as Spark Shocks, that can immobilize opponents in their tracks.

Snake Man is a tenacious Robot Master with a snake motif that was created to investigate narrow areas. He is the first Robot Master with an animal themed design. Snake Man is prudent and prefers to chase and corner his opponents, and attacks with snake-like missiles called Search Snake that crawls on surfaces. In Super Adventure Rockman, Snake Man appears in the underground passage in Episode 2, and he can dig underground to stay out of Mega Man's range.

Gemini Man  is a Robot Master from Mega Man 3, created by Dr. Light and Dr. Wily. He is capable of doubling himself, and uses that power to confuse or overwhelm his opponents. However, even without a clone to help him, he is a very tricky opponent to deal with, especially when he brings his Gemini Laser into play. He is a narcissist, and likes to admire himself in a mirror or with his double. Gemini Man also has a hatred and fear of snakes, mainly because his weakness is the Search Snake. Search Snakes can quickly eliminate Gemini Man before he can use his Gemini Laser.

Giant Suzy is a boss from Mega Man III. It can travel in any direction and has the ability to jump.

Drill Man was created by Dr. Cossack for underground construction and mining until he was reprogrammed to be a combat robot by Dr. Wily in Mega Man 4. His main weapon, the Drill Bomb, is intended to pierce dense objects and explode, causing as much damage to the object as possible. Like Crash Man and Spark Man, Drill Man has no hands. Instead, he has two powerful, all purpose drills made for grinding through solid rock and dirt, which he incorporates into his attacking strategy.

Dust Man is a Robot Master with a built in vacuum cleaner, originally created by Doctor Mikhail Cossack to be used for sanitation, being able to inhale various types of garbage. His powerful suction power got Dr. Wily's attention and he was modified into a combat robot, and fights against Mega Man in Mega Man 4. Dust Man's main weapon is Dust Crusher, a large piece of scrap metal that launches shrapnel in several directions. He can also pull opponents towards himself with his vacuum.

Dive Man is an aquatic-themed Robot Master based off a submarine. Dive Man was created by Dr. Cossack for deep sea exploration. When modified for combat by Dr. Wily however, he gained the ability to launch special homing torpedoes from his chest that can utilize two different propulsion systems - screw propulsion for underwater usage and jet propulsion for land. Due to a design error, Dive Man can also attack by launching himself forward like a torpedo, crashing into his foes to do major damage. Ironically, although he is an aquatic robot, he can get motion sickness.

Skull Man is a Robot Master created specially for combat with balanced offense and defense by Dr. Cossack while he was working for Dr. Wily in Mega Man 4. He attacks with shots from his arm cannon, and can generate a skull-shaped energy shield called the Skull Barrier for protection. Skull Man only moves or attacks when Mega Man does the same; however, he doesn't move if Mega Man only jumps.

Now here is a music reference that's pathetically obvious. I mean, Punk clearly looks the part of the music genre that he's named after. One tough customer, in the Game Boy version of Mega Man III, it was best to avoid getting hit by Punk himself or his Screw Crusher. Punk could destroy Mega Man in a mere 3-4 hits and was completely invulnerable when rolling at Mega Man in ball form. Woe to the player that lacked sufficient dodging skills or had zero E-Tanks. Punk is the only Mega Man Killer to have a Net Navi counter part in the Mega Man Battle Network series. This is all because Mega Man bigwig Keiji Inafune views Punk as one of his favorite creations.