Go'yavec is a kaiju of titanic size. In appearance, it resembles either salamander or crocodile with the entirety of its body seemingly made of earthen matter akin to mountains, even having plant-life growing all over it. It has red eyes, a large mouth full of conical-shaped teeth, and blunt claws on each limbs. Go'yavec also has multiple volcano scutes on the back and head to project multiple magma balls.
Being created as an oversized kaiju, Go'yavec possessed immense strength and durability thanks to both its size and rock-like outer layer that surrounds his body. While blunt and oversized, Go'yavec's claws were still impressive weapons in their own right, capable to raze parts of a mountain and even sending Gridman flying like a gigantic club. Suggestively, due to the size of its maw, Go'yavec should be able to swallow other kaijus whole.
Go'yavec's most powerful weapons however, are volcano-like growths on its back that fire a salvo of condensed balls of magma with enough firepower to set the entire forest ablaze. While destructive and able to seriously injure Gridman, these magma balls are fired with great inaccuracy so that they inflict greater damage on the environment than intended target.
In spite of its immense defensive and offensive capabilities, Go'yavec has two weaknesses: One is its immense size that made it an easy target and another is its armor that is suspectible to continuous heavy firepower.
Go'yavec's sculpture was created by Akane prior to the school's whitewater rafting trip. She designed it to be larger and tougher than previous ones so it could overwhelm Gridman with sheer size.
Once certain that Yuta was Gridman, Akane contacted Alexis via her smartphone and instructed him to deploy the kaiju. Soon, the oversized kaiju appeared and wreaked havoc with its magma balls, creating a forest fire. Due to the Junk computer still being in Rikka's shop, Yuta, Sho, and Rikka had to go to a nearby phone booth to contact NGJHS to bring them the Junk by train. The trio then made haste to the train station, but in the process Yuta got separated from his friends when he tripped and fell, but was able to press on in spite of leaving his vest behind. This made the others worry until Gridman showed up, demonstrating that Yuta was okay.
Gridman and Buster Borr fought Go'yavec, but soon met resistance from Anti as well. This prompted Buster Borr to restrain Anti with his adhesive missiles, giving the Hyper Agents enough time to combine into Buster Gridman form. However, the battle went to a stalmate when Anti fired an organic copy of Buster Gridman's missiles. Not wanting to waste their time with Anti, Buster Gridman decided to overwhelm Go'yavec with his laser minigun/missile launching pack hybrid, and finished it with Twin Buster Grid Beam. This killed it and caused its remains to bury Anti alive.
Anti survived, but unlike in the city, the damage done to the woodland by Go'yavec was not reversed.