What kind of a coworker would you call this guy?

Quitting won't do you any good because there could be someone equally as evil at your next job. My first move when he pulled that **** about not covering for you when he was asked to would have been to tell him its policy that you can't leave without someone covering for you and second that he was told to do it by your supervisor and if he refuses, you have no choice but to go right back on your radio and tell your supervisor what happened. This guy is a blowhard that needs to mind his own business when it comes to your family and finances.