Ah yes, the promotion you're referring to might be the series 'The Batman Adventures' released by DC. This was intended to tie-in with the then-airing Batman: The Animated Series and was indeed packaged with some cereal boxes. Limited prints = hard to find now. Frankly, it's quite a gem for …

Professional comic collector here. I believe you're referring to Gotham City Limit, an institution of the comic book world. What really sets them apart though is their range. They not only deal in mainstream comic franchises but also have a respectful representation of indie and less-known comics. Their vintage collection …