Valkotukka
From Tolkien Gateway
Valkotukka was a minor character in The Father Christmas Letters. He was a polar bear cub. Valkotukka had a brother named Paksu, and he was the nephew of the North Polar Bear.
History
Valkotukka, along with Paksu, came for a visit one Christmas to visit their uncle and Father Christmas. The two never left.
Valkotukka, just like his brother, was mischievous and naughty, to the extent that Father Christmas wrote of them; "they seem to be growing up just like their uncle."