Snake from Canada on loose (8)
I believe the answer is:
anaconda
'snake' is the definition.
(anaconda is a kind of snake)
'canada on loose' is the wordplay.
'loose' indicates an anagram (letters are loosened from their original positions).
'canada'+'on'='canadaon'
'canadaon' with letters rearranged gives 'ANACONDA'.
'from' is the link.
(Other definitions for anaconda that I've seen before include "Water-boa" , "Snake of the boa family" , "Huge South American snake" , "A slippery customer" , "crawler" .)