Ever since his absence, however, Doctor Surlee later took over to continue the tradition.
Polar Bears did not exist in Toontown Online. Canonically, Slappy was unfortunately not around at the time to offer Polar Bears, and majority of Polar Bears likely disappeared after the Doomsday attack.
Bears are the only Toon species that can become white. They are also one of the only two species that can obtain a special color, alongside cats.
There are similar cheesy effects like this for all Toons called "No Color" and "Polar Toon". These two effects are the same, but have a slight difference: they do not turn the laff meters white, and do not last permanently.
There seem to be Polar Bear faces on some of the shop billboards in the streets of The Brrrgh.
Paula Behr, who offers the "Polar Toon" effect, is the only NPC that is a Polar Bear. She received her white color from Slappy.
This can be debated on whether this still remains true or not due to the arrival of Snowman and the other Snowtoons, as most of them are bears with a white color. It is unknown if they are actual Polar Bears, or are under the influence of the "No Color" cheesy effect.
The Toontown Rewritten Wiki has a Toontastic collection of images and media related to Polar Bear. Feel free to check it out!