During Sonic the Hedgehog's and Miles "Tails" Prower's visit to Sandopolis Zone in an attempt to reach Lava Reef Zone in pursuit of Dr. Eggman, they encountered and defeated the Guardian, who appeared from a giant pyramid that rose from the ground. (VG: SH3aK)
When Knuckles the Echidna later passed through Sandopolis Zone to reach Lava Reef Zone in pursuit of a fleeing EggRobo controlled by Dr. Julian Snively, Dr. Eggman's assistant, after multiple encounters on the island, he, just like Sonic and Tails before him, encountered and defeated the Guardian, who appeared from a giant pyramid that rose from the ground. (VG: S3aK, SU: #70)
Eclipse the Darkling later passed through the Sandopolis Zone with the Dark Arms, who were carrying the Master Emerald, in an attempt to reach the shuttle that Team Dark had landed in Launch Base Zone. Along the way, he encountered the Guardian as one of the traps that Rouge the Bat had activated in an attempt to slow him down until Knuckles the Echidna and Shadow the Hedgehog could reach Eclipse. Given that he was seen later in other areas, Eclipse presumably defeated the Guardian. (SU: #70)
- Guardian was based on the sub-boss of the same name in the Sega Genesis video game, Sonic the Hedgehog 3 & Knuckles. It was unnamed in the comic, but its name is considered tier 2 canon by this site's canon policy, as it does not contradict already established canon from tier 1.