NEW YORK, May 4 (UPI) -- Jeffrey Dean Morgan says he never gets tired of playing Negan because the Walking Dead antagonist is always growing and adapting to new situations. "After all the years of playing one character, it's the amount of growth that I think that Negan's had and the different sides of Negan that we've been able to show [that are satisfying]," Morgan, 59, said at a recent New York Comic Con press conference. "I hope that I grow as a human being, as well, but in different ways