A snake makes an unusual present (7)
I believe the answer is:
serpent
'a snake' is the definition.
(I know that snake can be written as serpent)
'an unusual present' is the wordplay.
'an unusual' is an anagram indicator.
'present' with letters rearranged gives 'SERPENT'.
'makes' acts as a link.
(Other definitions for serpent that I've seen before include "(In literature) a snake" , "exhibit at zoo" , "the first lady found beguiling" , "Devil of a snake" , "Limbless reptile" .)