Polar Bears

[jeffbwood]

Why do polar bear's have blue tongues?!

[sft42]

Because it's bleedin' freezing! No, they have black skin as well underneath all that white fur so the blue tongue just matches up...as to a reason for being that actual colour i'l have to pass.

[Cetti]

Although it is hard to see beneath their white fur, polar bears have strongly pigmented, deep black skin. This allows them to absorb much more heat than pale skin and so helps to protect them against the icy cold Arctic. It is possible that the pigmentation of the skin has extended to pigmentation of the mucus membranes (including the tongue).
Polar bears do not sweat through their skin, and their paws are also unsuitable for heat regulation, being thickly callused to prevent the bears from cutting themselves on sharp ice edges. The bears therefor regulate heat, like dogs, by panting. The tongue is then blue as a result of high blood circulation.
http://www.awi-bremerhaven.de/ClickLearn/newFAQ/FA
Q_Eisbaer-en/Fauna8-e.html

[xyzzyplugh]

but the fur isn't white. - it's translucent. :-)