As photo shoots go, it was somewhat atypical. Sure, the ingenue wore fur, and attendants were suitably admiring. But the subject was shockingly young, and the photographers' dizzying demands produced a foot-in-mouth—er, -bowl—moment or two. Before long, the poor thing was worn out and needed some beauty sleep. Knut, a polar-bear cub born at the Berlin Zoo, amiably bared all for Annie Leibovitz and Vanity Fair's Green Issue cover, which he shares with a not quite as hirsute, though suitably cute, Leo DiCaprio. And a star is born.