Greenman vs. Alien Dorok (グリーンマン対ドロク星人, Gurīnman tai Doroku Seijin?) is the eighteenth episode of Go! Greenman.
As per usual, Maoh's enraged screams and Tonchiki's pathetic reassurance echo through the Underworld. After the mild conflict, they break and Tonchiki arrives near a group of children playing a blindfolded tag-type game, with Alien Dorok close by. The game's seeker, who's blindfolded, wanders right into Tonchiki while searching for the other children. Confused as to what the object he's just walked into is, he ignorantly begins to walk back and forward into him over and over. This gives Tonchiki time to summon Alien Dorok closer, who grabs the child from the back. The other children realize what's happening and use a Green Call in their distress. As to be expected from Greenman, he instantly appears before them and goes after Dorok. They begin to exchange punches, and Alien Dorok shows off his rather impressive grip. However, it turns out Dorok was only distracting Greenman, and Tonchiki was escaping with the child! Luckily Greenman quickly realizes, pushes the child off to the side and dropkicking Tonchiki with all his strength. After that incursion, Greenman presses on battling Dorok. He fights strategically, keeping his distance for most of the time in order to ensure he isn't grabbed again. Albeit using somewhat foolproof maneuvers, Greenman is incapacitated once more. Alien Dorok independently moves the tentacles on his head, and trips Greenman by pulling his foot out from under him. Tonchiki, still lingering on the battlefield, crushes Greenman's chest with his foot while ordering Dorok to use his ability. This happens to be an inky, black, cloud which permeates in the air. Though, the attack doesn't work out as planned; Greenman jumps up as soon as the substance leaves Dorok's mouth, leaving only Tonchiki to get hit. Now partially blinded, Tonchiki stumbles away and leaves the two to fight it out. Suddenly, Greenman decides to grow to giant size, towering over the now ant-sized monster. Alien Dorok grows as well however, and they fight, yet again. After another quick tussle, Dorok erratically fires ink from his mouth, which impairs Greenman's vision in the left eye. At this point, fighting is extremely difficult, close to the point of impossible. Alien Dorok once again trips Greenman, but this time begins to beat on him while still on the ground. And, once close enough to Greenman's face, Dorok blasts him in the other eye and leaving him completely blind. Alien Dorok takes advantage of Greenman's newly created handicap, continuing to whale on him and even constricting him with his tentacles. Greenman does manage to break free, and tries an ability by shouting "Greenman Cut". But, this ability definitely does not work as his machinery begins to fail. Miraculously, Greenman starts to wander away and tries the ability once more, this time with it functioning perfectly. Powerful lights flicker on in his eyes, and the ink is melted away. Fully functional once more, Greenman flips Dorok to the ground and destroys him with a mere Leg Arrow.