Simply a person that will do anything for a "bag" of dope(meth,coke,weed,heroin,etc..). Primarily busted-ass 20 yr-old looking 40 females. The kind that make you go "WTF!" when you have the distinct displeasure of runninginto one face to face.
Can you believe that girl? She took her 2 yr-old on the bus at 1am to go suck her dealer's cock for a rock! What a bag chaser!