id go to managment. why should someone get paid for slacking or harrassing someone. and turn into a psyco like someone else mentioned and make him afraid of you to the point where if he threatens you again look him straight in the eyes and tell him his favorite chilli.. was his dog..

i do carry out at a grocery store.. bagging basicly the same thing you do and there are slackers but not bullies, just do your best dont stop, plus the good thing about being the hardworker.. you can be the one to take the groceries out to the hot chicks car that comes in once a week and score a phone number... you can do the same..