Muddled as a mammoth? (6)
I believe the answer is:
woolly
This clue is a double definition.
'muddled' is the first definition.
(I know that muddled can be written as woolly)
'a mammoth?' is the second definition.
(woolly mammoth is a kind of mammoth)
'as' is the link.
(Other definitions for woolly that I've seen before include "-- Bear; -- mammoth" , "Confused and vague" , "description of mammoth?" , "Unclear" , "as 3 [ROMNEY] ?" .)