Church treating one lame animal (9)
I believe the answer is:
chameleon
'animal' is the definition.
The answer is an example.
'church treating one lame' is the wordplay.
'church' becomes 'ch' (common abbreviation).
'treating' indicates an anagram.
'one'+'lame'='onelame'
'onelame' is an anagram of 'ameleon'.
'ch'+'ameleon'='CHAMELEON'
(Other definitions for chameleon that I've seen before include "Creature adding colour" , "Lizard that can change its colours" , "colour changer" , "Colour-changing lizard" , "Small lizard able to change colour" .)