Vexy and Hackus were major antagonists featured in the 2013 sequel The Smurfs 2.
Vexy is a female mischievous being that was grey along with Hackus, she wants to find Smurfette to spend the time with her as sister with the help of her brother Hackus. Hackus is a male mischievous being who has a goofy tongue with bad taste of prank. He wants to reunite his sister Smurfette back together as siblings, they are better known for their tricking skills to spend the time with Smurfette.
Gargamel turns Vexy and Hackus into real Smurfs like Papa Smurf before him, he tried to destroy the Smurfs, but Patrick, his father manage to rescue the Smurfs, Smurfette, Vexy and Hackus from Smurf essence by overpowering Gargamel and order Smurfette to send Gargamel back to his house on the Smurf Village.
The Smurfs, Smurfette, Vexy and Hackus manage to return home to find their friends in time for Smurfette's Birthday after Gargamel is attacked by Azrael. Vexy and Hackus become the new members of the Smurf Village, then Vexy falls in love with Grouchy Smurf. Meanwhile Gargamel is attacked by his own pet cat Azrael as the movie ends.