Spectators and international media flocked to the Berlin Zoo on Friday for the public debut of Knut, the puppy-sized polar bear cub that has charmed Germans and ignited intense debate among animal rights activists.

Crowds snapped pictures and squealed in delight as the three-month-old cub rolled on the grass, splashed in a pond and gnawed at a chunk of wood, but the controversy over Knut is not your usual warm-and-fuzzy animal tale.

Knut plays with his keeper, Thomas Doerflein, at his first public appearance at the Berlin Zoo Friday. Television crews and photographers jockeyed for position with hundreds of children for a glimpse of the polar bear cub.
(Herbert Knosowski/Associated Press)

The 19-pound cub was raised by humans after his mother, rescued from an East German circus, rejected him and his brother. The pair were left to fend for themselves and Knut's brother died soon after, which is when an animal handler intervened to save Knut.

The handler and Knut have bonded, but some animal rights groups have argued those life-saving measures were a violation of animal rights and that nature should have been left to take its course.

The Berlin Zoo, which has begun selling Knut stuffed animals and other souvenirs, rejected the idea that Knut might be better off dead than dependent on humans.

"We are not worried about Knut's future," Berlin Zoo vet Andre Schuele told reporters. "As a male, he will grow big and strong. Polar bears are loners and he will be fine — it doesn't matter that he has been hand-reared."

Friday was declared "Knut Day" at the zoo. Starting Saturday, the general public will be invited to see Knut, who will make brief outings to play with his handler.