I had somebody here searching for this, so while it does not at all pertain to San Antonio music, I will attempt to answer the question: As I understand it -
Rob Zombie's real name is Robert Cummings. He changed it to Zombie due to his love of horror flicks.
His brother, Mike Cummings, is known as Spider, from Powerman 5000.
Hope that helps.
Covering San Antonio's music scene since 2005