@Frank Garret,
What was the situation when you worked together? Were you competing against each other for work, raises, a promotion, better hours, something else?
Because his behavior on the job sounds like a guy who was competing by trying to badmouth his competition.
BTW, most coworkers and supervisors see through that sort of nonsense. A working environment where everyone works together as a team is better (and cheaper to run!) than one where people are miserably competitive and cutthroat against each other.