The Ultra-robots, alternatively called Ultrabots, are eight specially designed intelligent killing machines made to hunt down and eliminate Samurai Jack. They appear in "Episode XVIII: Jack and the Ultra-robots" and the video games Code of the Samurai and Cartoon Network: Punch Time Explosion.
The eight Ultra-robots were created by Extor, against his will, to solely hunt down Jack. They were each given their own unique weapon, studied Jack's fighting skills many times, and were powered by Aku's evil essence. After Extor completed them, Aku decided to test them on his village, decimating Extor's home.
The eight Ultra-robots first appeared after Jack had begun his search for what had been destroying several villages. He soon came upon eight identical baskets, who revealed themselves as the Ultra-robots; they explained that they destroyed the villages to lure out the samurai. Jack tried to fight them, but discovered he couldn't even damage them. He soon managed to reach safety thanks to the Ultra-robots' creator, Extor. After explaining the origins of the malevolent machines, Extor gave Jack a special gauntlet that would increase his physical power and help him cut through the Ultra-robots.
Soon, Jack found the Ultra-robots again and used the gauntlet to destroy seven of the eight robots, but the gauntlet ran out of power before he could do the same to the final opponent. Desperate, Jack called upon the Gods who forged his sword many years ago. The Gods answered his call, empowering his sword with divine energy and allowing him to destroy the last Ultra-robot, ending their menace for good.
Their existence presumably has been erased after the past Aku's destruction, since he was no longer existed to order their creation.
Apart from their unique weapons, the Ultra-robots have identical designs; a thin body made of black metal (apart from their upper arms, which are light grey) and cylindrical heads with two glowing red eyes that flash when they speak. They have what appears to be wicker armor on their bodies, allowing them to disguise themselves as baskets by compressing themselves and retracting their limbs.
Although they are not the most physically imposing machines, these eight are terrifyingly strong; they were able to destroy countless villages despite being severely outnumbered, and gave Jack a terrific fight even after he gained the means to harm them.
Being assassin robots built solely to kill Jack, the Ultra-robots have little personality; what traits they do exhibit are likely influenced by the essence of Aku that powers them. They are extremely brutal and willing to do anything to draw out their target, leaving a trail of ravaged villages and mangled robot bodies in their wake specifically to incite Jack's anger and draw him to them.
On the rare occasions where they speak, the Ultra-robots use short sentences that tend to link with each other, indicating their shared origin as weapons of Aku. They speak in deep, monotonous voices, but appear capable of rudimentary emotion; in particular, the katana-wielding Ultra-robot appeared to briefly gloat when it had the upper hand on Jack and displayed astonishment when Jack turned the tables.
Powers and Abilities
Each Ultra-robot has incredible speed and strength, but their greatest asset is their nigh-indestructible armor plating called adamantium; not even Jack could cut through them on his own. They also have a special vision mode that enables them to find targets that would normally be hidden by obstructions, such as smokescreens.
Additionally, each of the eight assassins has a special weapon that is designed specifically for each one. Between the eight of them, they are capable of leveling entire cities and beating Jack to the brink of defeat.
- Flamethrower Ultra-robot: This robot had a pair of incredibly powerful flamethrowers instead of hands that could incinerate entire streets and buildings. It can also cloak its entire body in fire, enabling it to charge through most obstacles and create intense bursts of heat. It was the first one to be destroyed when Jack cut in half and blew it up with its own flamethrower.
- Chain-Claw Ultra-robot: This robot's hands were blade-like claws connected to chains that could be fired and retracted at will. It was the second one to be destroyed; Jack cut off one of its hands before horizontally bisecting it.
- Wire Ultra-robot: This robot stored a roll of explosive wire in its body, firing segments of the cord from a port on its stomach. It was the third one to be destroyed after being stabbed in the chest by Jack and accidentally getting shot to pieces by its comrades.
- Shuriken Ultra-robot: This robot had a propeller-like torso that could fire shuriken at high speeds, creating a deadly barrage of razor-sharp projectiles. It was the fourth one destroyed, being accidentally shot to pieces by the Gatling Ultra-robot.
- Gatling Ultra-robot: This robot's arms ended in powerful gatling guns, allowing it to fire projectiles at the same speed as the Shuriken Ultra-robot. Its bullets proved to be extremely powerful, being able to pierce the armor of its fellow Ultra-robots despite it being nigh-indestructible. Jack exploited this to trick the Gatling Ultra-robot into destroying two of its comrades before making it the fifth casualty of the battle, cut horizontally at the waist and neck, then having its head vertically bisected.
- Buzzsaw Ultra-robot: This robot's arms were equipped with large buzzsaws that could cut through solid rock as if it were paper. It was the sixth one destroyed; Jack cut off its left arm before slashing it across the chest.
- Gauntlet Ultra-robot: One of the more dangerous Ultra-robots, this robot had large gauntlets for hands that made it powerful enough to smash solid objects. It was also equipped with a cloaking device, letting it sneak up on targets to deliver a swift pummeling. It was the seventh Ultra-robot to be destroyed; Jack identified its location and subsequently cut it to ribbons. It was also the last of the group to be destroyed with the help of Extor's power-enhancing robot arm; after destroying the Gauntlet Ultra-robot, the arm ran out of power, forcing Jack to discard it.
- Katana Ultra-robot: The final Ultra-robot had no built-in weaponry; instead, it carried a high-tech black katana. It was a deadly swordsman with skills rivaling Jack himself; coupled with its adamantium armor, it managed to put him on the defensive even after all of its allies fell. It was ultimately destroyed when Jack called upon the power of the Gods to increase his sword's power, letting him cut the last Ultra-robot clean in half. Its last words are "Unbelievable".
- They are first characters to be granted part of Aku's Essence in the series before the release of Season 5 and introduction of The High Priestess.
- Though they were directly infused with Aku's Essence, unlike the Cult of Aku who simply received it as means of worship.