Creature getting chained, unfortunately (7)
I believe the answer is:
echidna
'creature' is the definition.
(I know that echidna is a type of egg-laying mammal)
'chained unfortunately' is the wordplay.
'unfortunately' indicates an anagram (a bad or unfortunate spelling).
'chained' is an anagram of 'ECHIDNA'.
'getting' is the link.
(Other definitions for echidna that I've seen before include "Prickly creature" , "Oz native" , "One preying on the workers" , "Had nice (anag) -- spiny anteater" , "Australian creature" .)