After the babies dress up as monsters, Angelica tells them that they will remain the creatures they are forever, yet Chuckie doesn't want to be a werewuff forever and so must find a way to break the spell. Original.
This story well encapsulates what fans of the television series liked. It's interesting, though, that Tommy and the gang seem more noticeably autonomous in this book than is usual for the show, but I guess that could possibly be attributed to the fact that it takes place late in the series, chronologically speaking. It seems to me that it might have been easiest for this story to take place somewhere between the Rugrats series and its All Grown Up spinoff counterpart.