It was only a matter of time before Mark's secondary personality and memories began to take over. It happened gradually. He began speaking and acting like Amphibia during high stress moments. He suddenly showed off skills he'd only know from being raised as a gillperson. And he began to think of himself as a she.
The other former frat boys were too caught up in their own new lives to think of checking on Mark, living in a swamp with Amphibio and his growing collection of eggs and children. They were at ten now. Ten! Some of the former frat boys remembered Mark, but were too upset with him to want to reach out. As such, no one who knew the truth could remind him of his former life, and no one noticed Mark's changes.
Mark began to view his offspring as ugly, not because of their species, but because they did not fit the gillperson beauty standards. Except for his son Bufo and daughter Rana. Those two were pretty enough to be considered his children. The others, though? He was embarrassed to have laid them.
Then, Mark started weaving his own clothes, feeling that what Amphibio had purchased wasn't cute enough. He switched to adorable girly outfits and started doing his hair.
Finally, Mark had become Amphibia. A vain, feminine, spoiled gillwoman. One who had finally had enough with her lot in life.
Amphibia made her plan. She waited until she had just laid a spawn of eggs. Then, that night, before Amphibio could make her pregnant again, she grabbed Bufo and Rana and fled while Amphibio was sleeping. She made sure to grab some gold on her way out, to finance her trip.
The journey to her old home was long and arduous, but she finally returned to her family. She didn't realize this, having lost her human memories, but her family was the same as it had been when she was human, just now gillpeople. Her family celebrated upon her return, and accepted her son and daughter, her only attractive offspring.
Before long, Amphibia was back with her true love, the handsome Anura. He was so big and strong and gorgeous. He vowed to produce countless spawns with her and raise Bufo and Rana as his own. They were formally mated in a traditional ceremony.
A few months into being mated to Anura, Amphibia was laying their second spawn when...