Dook is an ordinary house ferret, if you overlook his grumpy demeanor and his dream to become a famous songwriter. He lived a life of peace and quiet (again, aside from the music) until the day he met Chessie. Since then, he's done his best to ignore her, hoping she'll eventually go away. It's not looking very likely.
Elizabeth is a mouse living in the walls of Dook's home. She doesn't socialize much with the animals on either side of The Window, and when she does, she can be very distant and soft-spoken...until she starts to sing. After hearing Dook's untrained voice, she decided to give him singing lessons so he wouldn't embarrass himself around her again.
Max is a mutt that lives in the same complex as Dook. On occasion, his owner will drop Max off at Dook's owner's place. Max's favorite pastimes are barking while hiding behind something (or someone), chewing on stuffed animal ears, giving Dook (and now Chessie) lots of kisses, and chasing down that elusive red dot that shows up from time to time.