Lurking beneath the lands of Sollgel, a huge arachnid lived. Standing much taller than a human being, the spider only came out from beneath the earth to feed every few months. However, during a scrap involving Minilla and a Kamacuras, a stray fallen rock awoke the mammoth sized killer. Rising from the ground, casting off the layers of thick earth, the massive spider attacked the first being it saw, being Riko and Goro. Running, and climbing the mountainside, the pair managed to escape the titan's wrath. Soon, however, the animal moved to the toward the human's new base, located in a cave below the Earth, and once again tried to feed. Having their backs against the wall, the terrified men managed to avoid the grabbing claw of Kumonga, leaving the spider's hunger to rage still.

It wasn't until Minilla strayed by did the devil have a chance for a meal. Springing from the tree cover, the spider cocooned the hapless young monster in a thick web. As he was about to move in for the kill, a Kamacuras revealed itself, and tried to fly by the scene, but Kumonga would not let it pass, and cocooned the armored insect. Staving the feel for nutrition, the animal injected its deadly venom into the prone insect, killing it instantly. Kumonga then moved on, about to do the same with Minilla, until Godzilla intervened. Throwing a rock, the monster battled the spider back. A long battle ensued, but in the end, Godzilla and Minilla set aflame the black body of Kumonga.

Surviving the wicked battle, the Japanese sought to remove the animal, while in its weakened state, to Monster Land. There, the creature was among the precipitants that the Kilaakian controlled when they invaded. Though humanity was able to sever the link, and send the spider into battle with King Ghidorah, alongside a host of Earth's monsters. Triumphing over the golden space dragon, Kumonga was returned to Monster Land where it lives to this day.