sentences:  He also performs experiments ranging from simple DNA tests to creating a genetic clone of Stan Marsh for his son's science project in "An Elephant Makes Love to a Pig".Mephesto also provides normal genetic testing services, as when Cartman has him determine who was his father in "Cartman's Mom Is a Dirty Slut" and "Cartman's Mom Is Still a Dirty Slut".Mephesto has a brother who attempts to kill him every month for unrevealed reasons, as mentioned in the aforementioned episode.