Spider is natural at scuttling (9)
I believe the answer is:
tarantula
'spider' is the definition.
(I know that tarantula is a type of hunting spider)
'natural at scuttling' is the wordplay.
'scuttling' is an anagram indicator (letters scuttle or move around).
'natural'+'at'='naturalat'
'naturalat' with letters rearranged gives 'TARANTULA'.
'is' acts as a link.
(Other definitions for tarantula that I've seen before include "spider to appear" , "small, venomous creature" , "Breed of spider" , "Large venomous spider" , "Leggy creature" .)