National Football League star Gilbert Brown goes from fat kid to phat Green Bay Packer in a spot titled "Phat," part of the league's "Feel the power" campaign. The 350-pound Mr. Brown is first seen in clay-animated form as a pudgy kid, taunted with fat jokes in a voice-over from rapper Chuck D. But then he grows up. Plays pro football. Suddenly, he's "phat" -- which in the parlance is nothing to joke about. NFL Films, Mount Laurel, N.J., created the spot, airing in league broadcasts through October. Director: Greg Kohs. Writer: Wendy Lapidus-Saltz.