A Stage Hand is someone who lacks real acting ability, yet still wants to be part of a stage production. Usually drama dropouts if you will, they do not appreciate the art or talent of actors.
A person who makes the impossible possible, usually in stupid yet functional ways. They also have to fix everything the actors break. For further information see ninja
A person you hate intensely not because they deserve such hatred but because they serve as a focus for your general hatred. A healthy way to dispense with excess animosity.
Jake's not really that big an asshole. He just serves as my hate sink.