So bats can change into crows! (6)
I believe the answer is:
boasts
'crows' is the definition.
(I've seen this in another clue)
'so bats can change' is the wordplay.
'can change' indicates anagramming the letters.
'so'+'bats'='sobats'
'sobats' is an anagram of 'BOASTS'.
'into' is the link.
(Other definitions for boasts that I've seen before include "Brags in praise of oneself" , "crows" , "Brags, blows" , "Blows one's own trumpet" , "Brags, shows off" .)