Nina dobrev latest pics of britney

Halloween is in full swing in Hollywood and the stars are dressed to scare and impress.

While Halloween is officially marked on the calendar for Oct. 31, celebrities will be celebrating all weekend.

Here Jessica Alba dresses up as Britney Spears from the "Toxic" music video and Kelly Sawyer Patricof attends as Spears from the " Baby One More Time" music video.

Next to them, Edward Norton and Shauna Robertson channel David and Victoria Beckham at the annual Casamigos Halloween party on Oct.

Scroll through for some of the best spooky, sexy and surreal costumes.

Justin Bieber and Hailey Bieber embody Pebbles and Bamm-Bamm from "The Flintstones" at Vas Morgan and Michael Braun's Halloween party on Oct.

Nina Dobrev and Shaun White (who's just out of frame) are Guns N' Roses while Miles Teller and Keleigh Teller