Bikkuriman is a series of stickers usually found in convenience stores packaged with a wafer. They've done several special editions in recent years, with baseball stickers showing up from time to time.
In 2015 and 2016, they did Tigers stickers. They were given away over a weekend at Tigers home games, and are difficult to find at reasonable prices.
I'm still looking for the '15 and '16 Tigers sets - 2015 has 12 card-size stickers, while 2016 has 13 (10 regular and 3 short print) standard-Bikkuriman-sized stickers.