Spiny egg-laying mammal (7)
I believe the answer is:
echidna
'spiny egg-laying mammal' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for echidna that I've seen before include "Insectivorous mammal" , "Creature with spines" , "One preying on the workers" , "Little animal" , "Australian creature" .)