At three months old, however, the playful 19lb bundle of fur is at the centre of an impassioned debate over whether he should live or die.
Animal rights activists argue that he should be given a lethal injection rather than brought up suffering the humiliation of being treated as a domestic pet.
"The zoo must kill the bear," said spokesman Frank Albrecht. "Feeding by hand is not species-appropriate but a gross violation of animal protection laws."
When Knut was born in December, his mother ignored him and his brother, who died. Zoo officials intervened, choosing to raise the cub themselves.
But Albrecht and other activists fret that it is inappropriate for a predator, known for its fierceness and ability to fend for itself in the wild, to be snuggled, bottle-fed and made into a commodity by zookeepers.
They argue that current treatment of the cub is inhumane and could cause him future difficulties interacting with fellow polar bears. "They cannot domesticate a wild animal," added Ruediger Schmiedel, head of the Foundation for Bears.