Some TMNT stuff really isn't for little kids.
Seri the Regenta of Y'Nood Minor, was the princess of the alien race known as the Protoceratons, and appeared in Volume 4 in the Mirage series. She may have been Michelangelo's most serious relationship. While he was meant to play tour guide, they both sneaked away from her bodyguards to tour the northeast coast.
Seri came to Earth on US soil to learn about Earth. While Michelangelo was supposed to be her tour guide, he does something very reckless; he convinces Seri to sneak away from her bodyguards so that he could take her on a tour of the northwest coast of the U.S. Michelangelo and Seri spend most of their time together, eating fast food and swimming. During a visit to the coast of Maine, Seri became fascinated by the lobster-fishing boats, and swam down to catch some herself, but was caught in one of the boat's fishing nets. Michelangelo saved Seri and revived her using CPR. Seri found the mouth contact very intimate, and was so enamored that she invited Michelangelo to mate with her.
The next day, Michelangelo woke up to discover Seri had laid a clutch of eggs. She called them "our children", strongly suggesting that Michelangelo was their father. Seri was very protective of the eggs, and Michelangelo went off alone to buy supplies to safely carry the eggs. But when he came back, Seri's bodyguards had caught up with her, and were already carting off the eggs. Michelangelo intervened, but they overpowered him and detained him. Seri and her bodyguards returned to their home world through the Utrom transmat, secretly smuggling both the eggs and an unconscious Michelangelo.
Michelangelo was imprisoned in an extrajudicial Styracodon prison, where he shared a cell with the Triceraton Azokk. One day in the prison courtyard, Michelangelo looked up to the top of the prison wall and saw a Styracodon woman who looked like Seri. Michelangelo desperately climbed the wall to see her, but the woman never spoke, and the guards denied that the Regenta would ever visit the prison. Michelangelo was knocked off the wall back into the courtyard, feeling betrayed by Seri.
Eventually, Michelangelo escaped from the prison with Azokk's aid, though Azokk died in the process. While wandering the planet's countryside, Michelangelo was rescued by Triceraton commandos who had originally come to rescue Azokk. Michelangelo joined forces with the Triceratons and left the planet, subsequently joining their commandos and participating in battles and genocide against Styracodons. His fondness for Seri turned into bitter hate as he swore he would seek vengeance against her.
Volume 4 is unfinished, so the fate of Michelangelo, Seri, and Seri's eggs has not been resolved.
- If she did in fact carry Michelangelo's children, Seri would be the first love interest who would have had a family with one of the Ninja Turtles. However, the series' hiatus has left the status of the brood in question.