Creature initially loathed Buddhist monk (5)
I believe the answer is:
llama
'creature' is the definition.
(I've seen this before)
'initially loathed buddhist monk' is the wordplay.
'initially' indicates taking the first letters.
'buddhist monk' becomes 'lama' (as in the Dalai Lama).
The initial letter of 'loathed' is 'l'.
'l'+'lama'='LLAMA'
(Other definitions for llama that I've seen before include "mammal that chews cud" , "Camel-like animal" , "Long-necked woolly animal" , "Peruvian beast of burden" , "Alpaca" .)