Furry carnivorous mammal biting stump (6,3)
I believe the answer is:
arctic fox
'furry carnivorous mammal' is the definition.
(I know this)
'biting stump' is the wordplay.
'biting' becomes 'arctic' (both can mean very cold).
'stump' becomes 'fox' (both can mean to baffle).
'arctic'+'fox'='ARCTIC FOX'
(Other definitions for arctic fox that I've seen before include "Northern mammal that turns white in winter" , "animal" , "creature" .)