Have you ever played a game and then a character from another game just appeared out of nowhere? If the answer is no, then it's totally understandable 'cause this is a highly specific topic.

Still, there have been a couple of instances where certain characters just cross-over for no reason other than the surprise of it; I personally adore when this happens and makes these occurrences exciting in a different way than if it was just advertised in the box. Again and as always, suggestions are always welcomed, especially in a case such as this where is so specific, it would be fun to discover what games meet the criteria!