The alphabet goes from A-Z, but I go from Z-A. What am I?

I drift like cotton through the blue, changing shape as dreamers do. I appear soft to the sight but not to hold, I paint the sky in gray or gold.

From earth's embrace, I take my form, Molded by hands, soft and warm. With water's kiss, I find my way, To become art that shall not sway.

A sea giant's treasure, for your nose's pleasure.

It has a nose that knows secrets. A mouth that mouthes no words. It speaks in the coat of a tree. Lovable, but hares bewares; It can be a bully.