Greenman vs. Stock (グリーンマン対ストック, Gurīnman tai Sutokku?) is the seventh episode of Go! Greenman.
Realizing Maoh is furious at him for his constant failure, Tonchiki tells him that he has a plan. So, Tonchiki teleports to the playground and makes his newest mutation, Stock, appear before the childrens' eyes. Frightened at the sight of the monster, the children run away before running into Tonchiki and eventually using the Green Calls to summon Greenman. Greenman flies in from space, landing on a slide, and confronting Stock. It is not long before they begin fighting. Stock is quickly beat down, with some interference by Cretin; however, as time goes on, the monster begins spitting pellets, creating a sort of barrier around himself. Because of this, Greenman is not able to inflict any damage on the monster, and is eventually flipped over a railing. As Greenman stood up once more, he thought to utilize his surroundings, and backed up into a swing which he used to kick Stock in the chest. Realizing his efforts were useless, Greenman used his Fire Fighting attack, which inflicted much needed damage on the monster. Now able to punch at Stock, Greenman was able to overpower it. It began to run away from Greenman, fearing for its life. So, Tonchiki made Stock grow to giant size, and Greenman did the same to continue the fight. Now grown to giant size, Stock could not only use his barrier, but was also able to breathe a toxic gas. After the short flow of gas, Stock began to run away again, but this time was stopped by Maoh and Tonchiki. The two unwillingly overworked the monster, causing it to drop to the ground. Assuming Stock was now defeated Greenman began to walk away, little did he know, Stock was alive and well. The monster quickly jumped up and grabbed Greenman from behind and threw him to the ground. Despite this unexpected attack, Greenman was able to hit Stock multiple times in his weakest point, his chest, causing him to drop to his knees and explode.