Weasel

Weasels are mammals mentioned only once in the Dragons: Rescue Riders episode, "Where There's Smoke".

Function
In the DreamWorks Dragons Franchise, weasels are mentioned as an epithet against sneaky dragons, specifically Cutter.

Dragons: Rescue Riders, Season 1
In "Where There's Smoke", Magnus Finke calls Cutter a winged weasel, as he messes up Magnus' Automatic Sheep De-Woolifying Machine by scaring off all the sheep.