Once simply the voice of a duck, Quack escaped through a series of highly coincidental but surprisingly likely events. He has later met up with other duck voices that have escaped, but they have moved on quite quickly. Escaped duck voices are not the most sociable beings in the universe, especially since they are constantly paranoid about getting tracked down and forced back into the duck.
Quack writes in the hope that he will become one with the words and never get caught.