Free dictionary online: translation in English, Spanish, French, Italian, Chinese, Russian, definitions, synonyms...
Results found in several dictionaries: Collins, Collaborative Dictionary
transformer (se) 
  vpr/vi to be transformed 
se transformer en  to turn into 
La chenille se transforme en papillon.  The caterpillar turns into a butterfly. 

Collaborative Dictionary     French-English
affermissement n. affermissement d'une clause ou d'une tranche conditionnelle : transformer en clause ou tranche ferme  
transformateur de vapeur n. Steam transformer ~ 
***
'transformer (se)' also found in translations in English-French dictionary
morph vt. se transformer Reverso General Dictionary 
pedestrianise nnpl. transformer en zone piétonne Reverso General Dictionary 
pedestrianize nnpl. transformer en zone piétonne Reverso General Dictionary 
pedestrianose v. (a) transformé en zone piétonne (past ind vt) Reverso General Dictionary 

"Collins English French Electronic Dictionary © HarperCollins Publishers 2005"