I checked to find a Croagunk in my black 2 game... And there wasn't any area to catch one!
Do I actually have to wait AFTERGAME to add a Croagunk to my team?
Yes. Sorry. Croagunk can only be found at Route 8, Moor of Icirrus and Icirrus City, which are all post game. Since the puddles are frozen over in Winter, Croagunk can only be found in Autumn/Fall, Spring and Summer.