The past history of the Amphibius of Earth-21993 mirrors that of his Earth-616 counterpart up until the point where Charles Xavier was going to be used as a weapon by the Skrulls to attack the Shi'ar empire. Xavier would escape this fate and return to Earth where he would be assassinated by Cable, sparking an explosion of attacks instigated by many of the X-Men's enemies.
Amphibius would join his fellow Savage Land Mutates would take advantage of Xavier's death to attempt to expand their empire beyond the Savage Land, clashing with the military. They would change their focus to attacking the X-Men directly at the ruins of the X-Mansion along with the Fenris and the Hellfire Club.
Later, when the US government would launch the Sentinels in response to Magneto, one of their targets would be the Savage Land Mutates. Of all the Savage Land Mutates, only Amphibius would survive the Sentinel attack and be placed into an internment camp. He would later be freed by Wolverine who would recruit him into a new team of X-Men.