Xavier the Villain is the primary antagonist of The Flintstones: On the Rocks. Xavier steals the diamond. Then he comes to the hotel where The Flintstones and The Rubbles are staying. He goes to the restaurant. The next day, Xavier goes to the swimming pool and happily meets Wilma and Betty. He writes a letter to Wilma. Then Wilma comes to the restaurant where Xavier is waiting. Xavier and Wilma dance with eachother. Xavier tells Wilma that it's not what she wants, It's about a diamond. In the battle, Fred, Barney and Betty have to stop Xavier from kidnapping Wilma. But it's too late. Xavier takes Wilma to his car. He escapes with her while Fred, Barney and Betty race to stop him.
Fred who is now on his own comes to the rescue. Then Fred remembers that he was dreaming about bowling. Well, It's not a bowl, It's a coconut. Anyway, When Fred rolls a coconut to knock Xavier to the bubbly fire, Xavier however laughs evilly. He tells Fred that he lost. Xavier tells Wilma to give him a diamond. Soon, Wilma did. Then Xavier lets go of Wilma so she can be in the fire. But Fred trys to punch Xavier. But soon, Xavier punches Fred. But at last, Wilma punches Xavier. Then the diamond flys to the spannish girl and Xavier is taken to jail.