Greenman vs. Gejiru (グリーンマン対ゲジル, Gurīnman tai Gejiru?) is the third episode of Go! Greenman.
Furious at Greenman for foiling his plans once again, Maoh consults Tonchiki to see if he has a new plan. Sure enough, Tonchiki presents his master with yet another monster, Gejiru. Gejiru is planted inside a remote control for a controllable toy, which had been being used by a small child. The remote control flew out of the child's hand and began smoking until it eventually released Gejiru. The monster chased him and his two other friends down a street until they summoned Greenman with the Green Calls. Greenman fought with Gejiru, who proved to be quite weak, as Greenman was able to beat him to the ground multiple times. Acknowledging this, Tonchiki decided to make Gejiru grow to a massive size. To continue their fight, Greenman also grew, and they pressed on. Despite now being grown, Gejiru continued to be beaten on. So, to even out the odds Gejiru used his secret weapon, a cannon in his arm. The blast damaged Grenman's electronics and significantly weakened him. He attempted to use the Breaster attack, but his electronics were damaged too severely for the cannons to operate. Realizing he could not fall back on his electronics, Greenman decided on using sheer brute strength to beat the monster. He leapt high in the air, and landed behind Gejiru, confusing him. The hero was then able to launch a surprise attack on Gejiru, throwing him to the ground multiple times and finishing him off with a combination of his still-working weapons including the Leg Arrow and Ear Boomerang.