Religious leader - the old cartoon character (6)
I believe the answer is:
popeye
'cartoon character' is the definition.
(I've seen this before)
'religious leader the old' is the wordplay.
'religious leader' becomes 'pope'.
'the old' becomes 'ye'.
'pope'+'ye'='POPEYE'
(Other definitions for popeye that I've seen before include "Spinach-eating sailor" , "Spinach and Olive Oyl lover" , "Old cartoon sailor" , "Cartoon sailor (showing amazement?)" , "Bluto's rival" .)