Porker Lewis, whilst living on the Floating Island, uncovered a temple in the Marble Garden Zone that had previously gone undiscovered. He was not the first to find it, however; an unknown visitor had experienced the cave's traps and scratched warnings into the wall for any future travellers. They were then killed by the Gizoid waiting in the main temple, although the figure had managed to seal the robot away.
In the present day, Knuckles the Echidna and Porker travelled to the inside of the caverns to discover the "ultimate weapon" of legend. In there, Porker investigated a highly technological capsule surrounded by ancient architecture. Before long, the machine had opened to reveal the Gizoid foreshadowed in the cave writings. Detecting intruders, the Gizoid lifted Porker into the air by his T-shirt and prepared to fight Knuckles.
The Gizoid soon realised Knuckles was the bigger threat and used a gravity weapon (similar to a Drakon Prosecutor's Drakon Sword's secondary ability) to temporarily hold the echidna in place. It then exhibited its ability to perfectly mimic the appearance and fighting style of its adversaries, growing knuckles and adopting Knuckles' brutal punches. The pair took the fight underground, but Knuckles tricked the Gizoid into tricking one of the traps that had plagued him earlier. The Gizoid was seemingly destroyed by a spike trap, but Porker learned that it had once come into contact with Chaos during the Great War, mimicing its ability to turn into a semi-liquid state.
The fight between the pair continued, until the robot revealed that the skeleton in the corner was the actual Gizoid, a term given to the guardian of the Chaos Emeralds. Knuckles deduced that the figure helping him through the traps was himself, something the robot did not believe. The "Gizoid" absorbed 8,000 years of data to investigate, something deemed to be too much for its circuits. Whilst breaking down and exploding, Knuckles punched its head off.
The Gizoid's appearance does not change much, but it does gain Knuckles' signature knuckles claws. When switching to subterranean mode, its fists transform into two large drills.
The Gizoid resembles a mix between itself and Chaos, still wearing its distinctive armour, though this has become just as malleable as Chaos' own liquid body as well as a lethal set of jaws.
The Gizoid looks largely like Emerl and other Gizoids from the Sonic the Hedgehog series. The main difference is its limbs, linked to the main torso by coils that greatly resemble a Guardian Robot. Its eyes are also narrower than Emerl's, enhancing its current status as a villain.