A "sport" involving a group of people intent on knocking a random person out with a single blow to the head. The group roams until they find a victim, and a member of the group approaches the victim generally from behind delivering the blow. This type of attack is also thought to be part of a gang initiation.
John was walking home from the bar last night when he passed a group of men on the sidewalk. The next thing he knows, he's on his back staring up at the sky with people looking down at him. According to someone who witnessed the attack, one of the men hit John once with an object or their fist and kept walking. According to the police, this sort of attack has been on the rise at the University of Illinois C-U campus and is known as "Polar Bear Hunting."