Knut still so cute ....

A combination of file photos shows polar bear cub Knut during the bear's first two days of public presentation at Berlin zoo, March 23 and 24, 2007. Germany's celebrity polar bear cub Knut has received an anonymous death threat, causing alarm at Berlin Zoo on Thursday and prompting heightened security. Knut, born on December 5, 2006, had to be hand fed every four hours by Berlin zoo employee Thomas Doerflein after its mother Tosca refused the baby.

Polar bear cub Knut plays at an enclosure in Berlin zoo April 19, 2007. Germany's celebrity polar bear cub Knut has received an anonymous death threat, causing alarm at Berlin Zoo on Thursday and prompting heightened security. Knut, born on December 5, 2006, had to be hand fed every four hours by Berlin zoo employee Thomas Doerflein after its mother Tosca refused the baby. REUTERS/Arnd Wiegmann

Polar bear cub Knut plays at an enclosure in Berlin zoo April 19, 2007.Knut has charmed millions around the world after he was born almost five months ago but rejected by his mother. His fate grabbed global attention after an animal rights campaigner said hand-rearing polar bears was a violation of animal rights. (Arnd Wiegmann/Reuters)

Polar bear cub Knut plays with employee Thomas Doerflein at an enclosure in Berlin zoo April 17, 2007. Knut may be loveable and friendly while he's still a wee cub but (polar) bears haven't been easy to train, Jon Aars of the Norwegian Polar Institute said. (Arnd Wiegmann/Reuters)