Old fool cuddles English cat (6)
I believe the answer is:
ocelot
'cat' is the definition.
(type of wild cat)
'old fool cuddles english' is the wordplay.
'old' becomes 'o' (abbreviation as in OT - Old Testament).
'fool' becomes 'clot' (I've seen this in other clues).
'cuddles' means one lot of letters goes inside another.
'english' becomes 'E' (abbreviation).
'clot' enclosing 'e' is 'celot'.
'o'+'celot'='OCELOT'
(Other definitions for ocelot that I've seen before include "Wild cat of the Americas" , "Type of American wildcat" , "Animal in the loo etc." , "Wild creature" , "Small leopardlike cat" .)