Hear me out. The Wolf and Cinderella's Prince are often played by the same actor. This is because they are in fact the same person. We meet The Wolf, who is killed before we meet the Cinderella's Prince. They are both very womanizing and, most importantly, have repeated lyrics. "...so many worth exploring | Just one would be so boring." How else would they both have known those words? Everyone thought the Wolf had been killed, but instead he regenerated when no one was looking. He then returned to the castle and attend the festival. Due to a freak accident his mouth is the door to his TARDIS, which is how he fit two whole people, totally alive, in his belly.