Knut's Best MomentsRemembering the world's most famous polar bear and his full four years of life

Credit: Peter Griesbach/Landov

Updated: Tuesday Mar 22, 2011 | 06:00 AM EDT

BRIGHT STAR

Born in December 2006 to a mother who rejected him, Knut was hand-reared by Berlin Zoo bear keeper Thomas Doerflein and adored by millions.