Here are some pics the celebs Tweeted/ Instagrammed (are you following me on Instagram? @nedahlstelio) while out celebrating Halloween.
Above, Alexa Chung as a Rydell High (Grease) student.
Lauren Conrad further enamours herself to us as Mary Poppins.
Heidi Klum as Cleopatra.
Joan Smalls as Raggedy Ann.
Anna Della Russo as the Pope.
Fergie as Lindsay Lohan.
Jessica Alba, Cash Warren and Honor as The Incredibles.