Feral

Maria's mother had a boyfriend named Harry Bellinger, who was an alcoholic and a cocaine addict who got Mrs. Callasantos addicted to drugs as well. Lucia's mutations began to emerge, much more slowly than Maria's, and caused her to start growing fur. When Lucia was seventeen, Bellinger tried to rape her, but Maria, now fifteen, whose mutations had emerged much more quickly, stopped Bellinger and killed him. Together, Maria and Lucia hid the body. Knowing that Maria had murdered Bellinger, Mrs. Callasantos killed Maria's pet pigeons in revenge. Seized by hatred, Maria then killed her mother.

Maria and Lucia went to live among the underground community of mutants known as the Morlocks. The two sisters came to resemble humanoid animals; Maria took the name "Feral", and Lucia became known as "Thornn".