A Halloween activity in which lazy, older kids wait around until the conclusion of trick-or-treating when the younger kids are about to head home with their bags stuffed full of candy for their parents to inspect, then they run up behind them and grab the bag out of the kids' hand without ever looking back, successfully scoring gobs of candy while exhausting minimal effort.
1. The only way my lazy fat ass is getting some candy this Halloween is if i do a buncha Bag Snatchin.
2. Man! We're too old to be out here trick-or-treating. Bag Snatchin is the way to go!
3. We'll wait until dark, then we're throwing on our masks, heading over to the slums, and going Bag Snatchin!