Animal from the east seen in parts of Wales (6)
I believe the answer is:
weasel
'animal' is the definition.
(I've seen this before)
'east seen in parts of wales' is the wordplay.
'east' becomes 'e' (abbreviation).
'seen in' is an insertion indicator.
'parts of' indicates anagramming the letters.
'wales' is an anagram of 'wasel'.
'e' going into 'wasel' is 'WEASEL'.
'from the' is the link.
(Other definitions for weasel that I've seen before include "Animal; sly person" , "This small mammal saw eel" , "E Wales (anag.)" , "Small mammal with short legs and long body and neck" , "Sly type" .)