Seal is transformed into Scottish girl (6)
I believe the answer is:
lassie
'scottish girl' is the definition.
(I've seen this before)
'seal is transformed' is the wordplay.
'transformed' indicates an anagram.
'seal'+'is'='sealis'
'sealis' is an anagram of 'LASSIE'.
'into' acts as a link.
(Other definitions for lassie that I've seen before include "''Will ye go ..., go'' (folksong)" , "Movie role for several dog stars" , "Scottish girl - canine movie star" , "Film and TV dog" , "girl found" .)