Animal's relative used to make a soldier's headgear? (8)
I believe the answer is:
bearskin
'a soldier's headgear?' is the definition.
(headgear worn by some troops)
'animal's relative' is the wordplay.
'animal's' becomes 'bears' (bear is a kind of animal).
'relative' becomes 'kin' (kin is a kind of relative).
'bears'+'kin'='BEARSKIN'
'used to make' acts as a link.
(Other definitions for bearskin that I've seen before include "Military fur hat" , "Regimental helmet of black fur" , "Pelt" , "Tall, fur regimental headdress" , "Busby" .)