Animal from a river in a Scottish island (5)
I believe the answer is:
brute
'animal' is the definition.
(I know that animal can be written as brute)
'a river in a scottish island' is the wordplay.
'a river' becomes 'r' (abbreviation).
'in' is an insertion indicator.
'a scottish island' becomes 'bute' (I've seen this in other clues).
'r' inserted inside 'bute' is 'BRUTE'.
'from' is the link.
(Other definitions for brute that I've seen before include "One monstrous" , "Beast - "Et tu ____ !"" , "Cruelly rapacious person" , "Wild animal" , "Caliban" .)