I think "rare" is directly proportional to when you met the character in relation to when the movie came out. I mean, a lot of characters are pretty readily available around when their movie came out/when they were popular, but are now almost impossible to find. For example, I have pictures of me with the Ninja Turtles and the characters from the TV Show Dinosaurs from when they were at MGM Studios. Now, that might be considered rare, but back then, they were all over the place. Similarly, and more recently, I have pictures of me with Hiro from Big Hero 6... again, back then, easy to find, now, not so much. A true "rare" encounter to me would be getting a pic with ANY of the Emperor's New Groove characters in the past 5 years while NOT at a Halloween party.