It seems GameStop have three exclusive Arkham Games Mystery Minis. Instead of Red Hood, Harley Quinn and Scarecrow, you’ll be able to find Joker with playing card, Detective Mode Batman or Mr. Freeze. You have a one in twelve chance of finding each figure (including the GameStop exclusives).
For those that don’t know, this set of Mystery Minis is based on the characters from the popular Batman video games; Batman Arkham Asylum, Arkham City, Arkham Origins and Arkham Knight.