Mammal (un)like fawn (5)
I believe the answer is:
camel
This clue might be a double definition.
'mammal' is the first definition.
(camel is a kind of mammal)
'unlike fawn' is the second definition.
'camel' can be an answer for 'fawn' (I've seen this before). I am not sure about the 'unlike' bit.
Can you help me to learn more?
(Other definitions for camel that I've seen before include "Beast of burden in desert regions" , "quadruped" , "Dromedary, perhaps" , "Humped beast" , "Yellowish" .)