Greenman vs. King Takoras (グリーンマン対キングタコラス, Gurīnman tai Kingu Takorasu?) is the thirteenth episode of Go! Greenman.
As per usual, the Underworld echoes with the yells of Maoh furious at Tonchiki who tries reassuring him. After hearing Tonchiki's plan, Maoh is hesitant to agree but does so anyways. Not too far away, a group of children are sightseeing, and one of them breaks away to urinate. However, he is stopped in his tracks by Tonchiki. The boy, as well as the rest of the children attempt to run away, but a cloud of pink smoke appears in front of them revealing King Takoras. They then dart the other way, but one of them trips and fearfully uses his Green Call. Greenman immediately appears, gliding through the air, and descending to the ground. Takoras flies into the air and lands near Greenman after being ordered to attack. Takoras begins whipping Greenman with his long tentacles which easily overpower the hero, not only by shear attack power, but by their ability to constrict him. Greenman continues to struggle, until he finally flips King Takoras who grabs him as they roll down a rocky hill. Once at the bottom, Takoras picks up a boulder and throws it at Greenman. He attempts to catch the large rock, but it is too heavy and causes him to fall over. They continue to attack each other until Tonchiki decides to make Takoras grow. Greenman also grows by means of his electronics and they continue battling, now in a small town. Greenman is not hesitant to attack, tackling King Takoras to the ground and beating on him. Maoh realizes this and consults Tonchiki who reassures him once more. Suddenly, Takoras jumps up and begins spitting a grey smog. Greenman is unable to handle the smog's effects and slowly begins to shut down. But, the onlooking children use their Green Call to repair him. Greenman charges straight towards King Takoras and leaps into the air with his leg extended. Takoras falls to the ground on impact and Greenman uses his Breaster attack to finish the monster off.