The zoo has just received a new baby — this one a pygmy hippo named Paul.
Now 6-months-old, Knut's keepers acknowledge they have over-indulged the polar bear. They say he is overweight and has to cut back on croissants and extra portions of fish, reports CBS News correspondent Shelia MacVicar.
According to the European Broadcast Union, Paul the hippo was born May 17 and zookeepers are hoping that he will draw attention away from Knut, who now is big enough to severely harm his caretakers.
But caretaker Uwe Fritzmann told the EBU that hippos can be difficult to raise.
"They don't get along with each other," he said. "So you can't keep them in large groups but mostly only on their own. Not every zoo wants to deal with that."
Knut also had an interesting childhood. He was raised by keepers after being abandoned by his mother. His daily romps with the keeper who hand-raised him were a huge and money-making attraction — more than 1 million people have come to the zoo to see him.
A true child star, he has spawned fan clubs and a whole line of merchandising. But like all child stars, Knut grew and grew, testing his teeth and his paws, until finally it became too dangerous to play.
Now one inadvertent swipe could badly maul his devoted keeper. But even as Knut grows up, and the crowds are not quite so entranced with a growing bear, Berlin is hoping they have a new child star in Paul.