Vexy is Smurfette's sister who was created by Gargamel and an member of The Naughties, she was responsable to kidnap Smurfette to take her in Paris. In the end of the movie, she becomes a hero along with Hackus and becomes a real Smurf like Smurfette was helped by Papa Smurf.
Vexy is voiced by actress Christina Ricci.
She originally was a Naughty created by Gargamel to serve him and his evil purposes, which include capturing Smurfette so that she would give the evil wizard the secret formula that would change the Naughties into Smurfs.
However, when she and Hackus did become Smurfs, they would soon be used as part of Gargamel's Smurfalator for extracting Smurf essence. After she returns to the Smurf Village, she sings the song "Ooh La La" and Grouchy Smurf falls in love with her. She also makes an appearance in the Smurfs' Village app for iPhone and iPad.