One day during Geology class, Buster suddenly had a terrible stomach cramp. Clutching desperately at his tummy, he was shocked - as was the rest of his class - to discover that he'd pulled a ball of raw biomass off of his own body. Before he could recover from that shock, the clay-like lump began expanding and mutating, quickly turning into a tiny Buster clone! Terrified, the clone tried to hide in Buster's fur, where it was swiftly reabsorbed into a now slightly-larger Buster. It wasn't long before he was recruited by NESTFART.