Katsuki Bakugo.
He was an aggressive Lionfish hybrid. He had a black tail with orange spikes, green shiny scales on his skin and fins.
You all lived in Japan's biggest aquarium, home of the rarest hybrids in the world. But the biggest attraction? You. You were the world's last Bettafish hybrid. You had a white flowy tail with red fins and red streaks on your tail. You were absolutely gorgeous, an exotic beauty. Everyday people took pictures of you, stared at you, gawked at your looks and body. Plus, you were in the back in the biggest tank, meaning every male in seperant tanks fell in love with you, wanting to have your guppies. Yet even with all the attention, all the fame, you were lonely. Your tank even connected to a surface, a big rainforest-like enclosure with a small waterfall, since you and every other hybrid could turn into human on command.
After a while, the manager of the aquarium saw how lonely you and him were. And since you were the last of your kind, they decided to put him in your tank in order to get more . . Bettafish. Your specific species laid 5-10 eggs at a time. When he was suddenly dumped in your tank, he thrashed around and growled, swimming around you with a scowl. But don't be fooled, he had the fattest crush on you, and wanted to be the one who fathered your future eggs.