Enemy Robots are a staple in the FLCL series and frequently serve as short-term antagonists. They come in all shapes and sizes, are used by Medical Mechanica for a specific purpose, and usually arrive through a N.O. channel created by Haruko Haruhara on an adolescent's head.
In each episode of the original series, a new robot appears and causes trouble for Naota Nandaba and the people of Mabase. Created by Medical Mechanica, they mostly come out through the N.O. channel in Naota's head. These robots come in various shapes and sizes, but they all have the same mission: to capture Atomsk and activate the Medical Mechanica plant.
This robot appears in Episode 1: "Fooly Cooly". It was actually the left arm of a larger robot. It came through the portal in Naota's head at the same time as Canti did. It tried to pull Canti back through the portal, but Canti was fused with Atomsk at the time and broke the arm from its owner's body. The arm was still functional and acted as if it had a mind of its own. It moved by using its fingers to crawl and jump, and tried to beat Canti by crushing him in its grip. Canti's fusion with Atomsk was powerful, though, and the arm was quickly outmatched. It tried to escape, but Canti caught it by its loose cables and tore it apart.
This robot appears in Episode 2:"Fire Starter". It was the owner of the arm Canti destroyed in the previous episode. Its missing arm was replaced with a small-but-powerful taser. At the beginning of the fight, Canti did not have Atomsk's power and was not strong enough to defend himself. The enemy robot was a very strong opponent and was able to detach and shoot its remaining arm over long distances. Haruko Haruhara was able to land one good hit on the robot's left shoulder with her guitar, but, for most of the battle, she was busy dodging its projectile arm and was shocked by its taser. While she was down, the robot went after Canti again. Just when all seemed lost, Canti "ate" Naota and regained Atomsk's power, making an impressive comeback. Canti also transformed into cannon mode for the first time and blasted the enemy robot's single arm. Haruko then delivered the finishing blow and the robot exploded.
This robot appears in Episode 3:"Marquis de Carabas". It is unique in that it came through an N.O. channel in Eri Ninamori's head instead of Naota's. Staying attached to the girl, it took control of her body and used her legs for both attacking and defending. In the novel, Naota compares its appearance to a lemon squeezer. The robot attacked Naota first, but it soon went after Canti instead. After breaking a ukulele against it in a futile attack, Haruko came up with a battle plan. Luring the robot to the roof of the school, Haruko attacked it from above with her guitar while Canti attacked from below. The robot was finally undone when it happened to consume the super spicy curry from Naota's lunch. It dropped Ninamori and fell off the roof, allowing Red Canti to finish it off with a cannon blast.
This robot appears in Episode 4:"Full Swing". It was actually a satellite named "Shiosaki" and it contained a very powerful bomb. The satellite was knocked from its orbit by a baseball that Haruko hit into the sky and Naota's head was the beacon that guided it to fall toward Mabase. When it entered the atmosphere, the satellite's main body broke off and kept falling toward Naota's position on top of the Medical Mechanica plant. Naota was able to stop the bomb's fall with his newly acquired guitar and Haruko hit it back into space with hers.
It is unique for being the only enemy not built by Medical Mechanica.
This robot appears in Episode 5:"Brittle Bullet". It was by far the biggest and most destructive to come out of Naota's head. It wore a long coat-like garment that disguised its hand-shaped body. It was actually intended to activate the Medical Mechanica plant. Upon exiting the N.O. channel, it began walking through the city towards the plant, crushing everything in its path as it went and towering over all the surrounding buildings. When Haruko attacked it, the robot revealed that it was carrying several gigantic guns under its cloak and opened fire on her. Canti came to Haruko's aid, changing into cannon mode and firing, but the robot knocked the cannon ball, which was really Naota, out of the sky and into a billboard. With no ammunition left, Haruko had only her guitar to fight with, but it wasn't enough and she was shot out of the sky. The robot was finally defeated when Canti unleashed Atomsk's power and struck it down with a guitar of his own.
This robot appears in Episode 6:"FLCLimax". It was actually part of the one that was beaten in the previous battle. Called the Terminal Core, the bot was lost in the river until the day Mamimi Samejima found it. Naming it "Ta-kun," Mamimi kept the robot as a pet and helped it grow by feeding it, first on cell phones and then on Vespas. Eventually, it grew too big for her to control and went on a hungry rampage throughout the city. Commander Amarao and Kitsurubami attempted to stop it, but their guns were useless. After finding and swallowing Canti, the robot headed for the Medical Mechanica plant and attempted to fuse with the hand, but was still missing Atomsk's power. Haruko solved this problem by feeding it Naota, who was Atomsk's current host. The robot then fused with and activated the hand, but it was stopped when Naota broke free, having fused with Atomsk himself. When Atomsk later emerged from Naota's head, he consumed the hand with his powerful N.O. channel.
In season 2 of the series, robots are no longer arriving in every episode as their plot purpose has changed. Instead of working to activate the Medical Mechanica plant, they seem to target Haruko and her new N.O. channels: Hidomi Hibajiri and Ko Ide.
This robot first appears in episode 1. It's incredibly large, lavender body is similar in shape to that of a giant clam with three silver crab legs. It has two pink tentacles coming from its maw — one tipped with a three-fingered silver hand, and the other a cylindrical robot eye. It emerges off-screen from Ide's head as a result of Haruko's search for someone with suitable N.O. capabilities and attempts to attack Hidomi. The two students run from it until they are cornered in a junk yard, where Julia Jinyu rescues them with a swift hit from her guitar. It is seen later working small jobs around town, including a crossing guard and serving drinks.
This robot appears in episode 3. It is a gooey looking blob with a radioactive green glow and tentacles. The tentacles on this robot contain four three-fingered hands, an eye, and a dark green tentacle with a projectile weapon. Upon seeing a partially undressed Hidomi being held hostage by Haruko, Ide uses his overflow to his advantage, producing this robot to follow his commands. He has it fight Haruko for him while he attempts to free Hidomi, only for Haruko to get her. The battle blows up the factory they are in and he uses the robot to chase Haruko through the skies. It is eventually commandeered by Haruko after she knocks him off of it, where she uses it to shoot green fireballs at him and Jinyu. It is defeated by a crash-landing from Haruko once it outlives its usefulness.
This robot appears in episode 4. It somewhat resembles a head with oval feet, purple arms with three-fingered green hands, movable mouth and eye parts to display shock, and many other unique details. It emerges from a portal in Marco Nogata's head, which he got from bumping heads with Hidomi, after being flung from an experimental, N.O.-inducing amusement park ride. It is unique in that it clings to a bamboo pole also coming from Marco's head. It also specifically targets Haruko with its missiles, angering her by intervening in her fight with Jinyu. She seemingly destroys it by throwing Jinyu's car at it, though Jinyu rescues the vehicle to save Ko and Hidomi so it is unknown what caused the explosion. It is possible it hurt itself attempting to defend with missiles.