Randomly, I had this idea recently for a studio/group of projects similar to ask blogs on tumblr. The story is that when Dipper and Mabel went into Stan's mind and all, and when they were trying to defeat Bill by altering reality, Mabel decided to give Bill another less harmful form. The form she chose was a cat. Once they left Stan's mind, Bill also came back to the real world. He decided to use Mabel's idea to his advantage, taking the form of a cat and letting Mabel take him in (much to the family's dismay). The reason he did this is so that the Pineses would warm up to him, and then he'd turn on them and attack BUT THAT'S LATER IN THE STORY. You'd be allowed to ask Cat!Bill or Cat!Will (I'm not certain on what his story would be, considering the fact that he's not as evil as Bill and he probably wouldn't plan revenge). Does this sound even remotely interesting? Please tell me in the comments. Also, a lot of this will probably not fit the canon, but that's the fun of AUs, they can be whatever you want.