Robo-Manus is one of the main bosses of the Battletoads series.
Robo-Manus is referred to as a Mutant Biogen: a half-organic, half-machine mutant monstrosity, armed with a potent array of weapons. He is notorious for having a different appearance, size and battle strategy in each game. Robo-Manus serves as one of the Dark Queen's two main guardians, the other being Big Blag. Additionally, given his frequent presence as a second-to-last or final boss, Robo-Manus may serve as the Dark Queen's second-in-command.
In his first ever appearance, Robo-Manus serves as the boss of Stage 8, the Intruder Excluder, where he is encountered at the top of the elevator shaft. Here, he is armed with a rapid-fire blaster that shoots a series of three projectiles which can quickly kill the 'toads if they hit. Additionally, he jumps around the platform in an attempt to crush the 'toads underfoot. It's worth noting that the speed of his jumps increases noticeably as he takes damage and his pattern of movement can become very unpredictable.
In the Game Boy version of Battletoads, Robo-Manus appears as the final boss in lieu of the Dark Queen, guarding the captive Rash and Pimple. In this game, Robo-Manus is much larger than he was in the original NES game and more closely resembles his depiction in artwork. Equipped with a pair of blaster cannons on his arms and capable of launching flaming, mortar-like projectiles from his body, Zitz must attack his arms and head with a mallet and destroy them to defeat him. As he takes damage, his attack speed increases considerably, and it's worth noting that even with his head destroyed, he can continue to attack.
In Battletoads and Double Dragon, Robo-Manus is encountered in the fifth stage, Missile Mayhem. Charged with flying a missile powerful enough to destroy the Earth, the 'toads and Dragons must fight their way from the tail-end of the missile all the way up to the cockpit and fight Robo-Manus at the missile's tip. This time, he's capable of firing laser blasts from his visor in a set pattern, jumping after each attack.
The difficulty of the fight largely depends on the version: The NES and Genesis versions are the hardest, as his laser blasts deal two blocks of damage, and the initial pattern he fires them in (One high shot, one low shot, and one middle shot) can successively hit the player enough to kill them. His jumps are also random in their direction and can kill the player instantly if he lands on them. After he's taken enough damage, his firing pattern changes (one high shot, one low shot) and his jumps become far more frequent and erratic.
In the SNES version, he is significantly weaker. His laser attacks only deal one block of damage, can't successively hit the player and follow the same pattern. He also only jumps in the same place and never moves unless hit by the player. Additionally, stomping the player only does two blocks of damage.
Robo-Manus appears as the final boss of Super Battletoads, and is far larger than he was in any of his previous encounters. This time, he attacks the 'toads on their spaceship at the end of the level and is fought in a series of phases.
During the first phase, he attacks from the side of the screen, unleashing barrages of missiles and streams of fire from his hands on the player. As he takes damage, his pattern changes and speeds up, eventually attacking with exploding drones and flamethrowers that appear from behind the player.
After taking sufficient damage, phase two begins. Robo-Manus will move below the 'toads ship where he will start flinging blue fire balls from his hands in random patterns at increasing speeds as they take damage. After taking enough damage, his arms will be blown off and the final phase begins.
During the third and final phase, Robo-Manus begins moving back and forth as he continually fires projectiles upward from a cannon on his back. Here, players must directly attack his head. After being dealt enough damage, a part of Manus' helmet is blown away, exposing his brains underneath and bringing up a status display of his shield power. He continues his attack pattern, albeit at a significantly increased speed.
Once his brain has taken enough hits, Robo-Manus will suffer a complete breakdown as his systems, singing Twinkle Twinkle Little Star, offering the 'toads coffee and wishing them Merry Christmas among other things before firing off one last series of blasts at the 'toads' ship and violently exploding, sending his mangled head slamming into the screen. Afterwards, he declares "I'll be back!" as the 'toads damaged ship limps away.