Animal is chained, unfortunately (7)
I believe the answer is:
echidna
'animal' is the definition.
(echidna is a kind of animal)
'chained unfortunately' is the wordplay.
'unfortunately' is an anagram indicator (a bad or unfortunate spelling).
'chained' with letters rearranged gives 'ECHIDNA'.
'is' is the link.
(Other definitions for echidna that I've seen before include "Spiny Aus. mammal" , "Oz native" , "Spiny egg-laying Australian mammal" , "Prickly creature" , "One preying on the workers" .)