Animal chained cruelly (7)
I believe the answer is:
echidna
'animal' is the definition.
(echidna is a kind of animal)
'chained cruelly' is the wordplay.
'cruelly' indicates an anagram (I've seen this in other clues).
'chained' anagrammed gives 'ECHIDNA'.
(Other definitions for echidna that I've seen before include "One preying on the workers" , "Prickly creature" , "Spiny Aus. mammal" , "Such a beast" , "Little animal" .)