Gejiru resembles a cross between an ant, a cockroach and a beetle. Gejiru is like a walking piece of abstract art in that is body is made up of many different colors, and his head isn't symmetrical, nor is it solidly colored.
Gejiru fought Junichiro Iwaki but was ultimately defeated.
Gejiru is the third monster to battle Greenman. The two fought in a city, with Gejiru pummeling Greenman using his arm cannon, but eventually Greenman won.
Gejiru has a great deal of strength, which he uses to his advantage when slapping opponents around with his limbs. He also has an arm cannon implanted on one of his upper limbs, which can shoot laser beams.