Holly Madison hosted “HollyWeen” at Studio 54 nightclub at MGM Grand, donning a gorgeous Queen of Hearts costume. She walked the red carpet and told reporters that she chose her outfit in hopes of having a Vegas-inspired ensemble.

Photo Credit: Erik Kabik/RETNA/erikkabik.com

Tabú Ultra Lounge at MGM Grand welcomed 90210’s AnnaLynne McCord as she hosted her little sister Rachel’s 21st birthday with a night of haunted seduction. The young starlet arrived at the Las Vegas hot spot with both her sisters Angel and Rachel McCord. AnnaLynne choose to dress up as a seductive catwoman.

Photo Credit: Erik Kabik/RETNA/erikkabik.com

Kellan Lutz and Ashley Greene of Twilight celebrated at TAO in the Venetian.  They are used to being dressed as Vampires for the new movie, “New Moon,” which comes out on November 20th, but for Halloween they dressed up a little different.

Sam Trammell and Rutina Wesley (who is a Las Vegas native) from True Blood partied at LAVO.   The four actors posed together for a group shot!

Photo Credit: Denise Truscello/Wireimage

Tabu Ultra Lounge at MGM Grand welcomed the cast of HBO’s True Blood including leading lady Academy Award-winning actress Anna Paquin, her on- and off-screen beau Stephen Moyer, Sam Trammell, Alexander Skarsgard and Kristin Bauer. As they posed for pictures on the red carpet, a sea of fans lined-up to get a glimpse of stars. All members of the cast stopped to shake hands and sign autographs as admirers gushed about their obsession with the show. The group brought along an entourage of friends and additional members of the hit series to celebrate the wrap of the first season and anticipation of season two beginning June 14.

Paquin, Moyer, Trammell, Skarsgard and Bauer partied together enjoying the high-energy of the award-winning lounge. Paquin and Moyer, the on- and off-screen couple, were seen embracing each other and kissing throughout the evening, never letting each other of sight.

Kristin Bauer, Stephen Moyer, Anna Paquin, Alexander Skarsgard and Sam Trammell (Credit: Tabu)