Animal from eastern terrain (5)
I believe the answer is:
eland
'animal' is the definition.
(eland is a type of antelope)
'eastern terrain' is the wordplay.
'eastern' becomes 'e'.
'terrain' becomes 'land' (I've seen this before).
'e'+'land'='ELAND'
'from' acts as a link.
(Other definitions for eland that I've seen before include "Large African deer with short spiral horns" , "One browses in the African plain" , "African beast" , "Laden (anag.); antelope" , "Large African antelope with spiral horns" .)