Adult Mutant Ninja Turtles
Master Sliver's Manchildren
The AMNT, Titian, Galileo, Erasmus, and Kepler respectively, are the group of turtles the party ran across in their trek through the sewers. Like them, the turtles were at odds with the Flesh Beasts. In fact, it was these very monsters that had removed them from their home, most heinously. Together, the Turtles and the Party fought and defeated Mim Mim and his Flesh Giant.
Master Sliver is the turtles Mentor and Guardian.