A flattened animal or person that is now dead. Usually found in parking lots but can also be described as a person who is lying on the ground burnt to a crisp or extremely stoned. Roggin' would be the adjective version of rog. This is usually said in a relaxed way. Can be substituted for pog as well.
Bro 1: Bro why is Ryan flattened out on the ground like that?
Bro 2: Nah he just Roggin' out man.