“I love Lady Taenya Scolex in the Pangolin Man show!” you go. And no wonder she’s your favorite character -- she kicks ass, has an amazing wardrobe, and flaunts a set of flesh-rending chitinous hooks to die for. But then you read the Pangolin Man books and, upon realizing that Taenya Scolex is a cosmetics peddler with one line (that line being, “Sorry, the restroom is out of service”) you understandably go, “Dude, WTF?”
This is more common than you think. Just look at all these (not made-up) examples, and marvel at how big a minor character can grow when transitioning to different media.