Final answer:
Fabulous Ducks doesn't appear to be a mainstream book, and without additional context, it's not possible to identify the most fabulous duck character.
Step-by-step explanation:
It appears there may be some confusion as Fabulous Ducks doesn't seem to be a widely recognized book or may possibly be fictional. When discussing literary works and their characters, it's essential to refer to a known book. Since Fabulous Ducks isn't identifiable in mainstream literature, it isn't possible to determine who the most fabulous duck is without more context or information about the book in question.