External guards called an animal (5-4)
I believe the answer is:
orang-utan
'animal' is the definition.
(I've seen this before)
'external guards called an' is the wordplay.
'external' becomes 'out' (similar in meaning).
'guards' indicates putting letters inside (inserted letters are guarded).
'called' becomes 'rang' (called on the phone).
'out' enclosing 'rang' is 'orangut'.
'orangut'+'an'='ORANG-UTAN'
(Other definitions for orang-utan that I've seen before include "Ape of Borneo and Sumatra" , "Angora nut for long-armed ape of Burma" , "Great ape" , "Species of ape" , "Endangered primate" .)