A pale and gaunt Mickey Mantle made his first public appearance today since a liver transplant a month ago, with this warning for kids: "You talk about a role model, this is a role model: Don't be like me." The Yankee great, whose 40 years of hard drinking helped destroy his health, has dropped 40 pounds, and has a 60 percent chance of living five more years. "God gave me the ability to play baseball and I wasted it," he said. "I'm going to spend the rest of my life trying to make up. I want to start giving something back."