The celebrity Halloween festivities continue, with stars like Lauren Conrad and Sarah Hyland hitting the spookiest parties in Hollywood. LC put together a remarkably accurate homage to the most iconic nanny ever: Mary Poppins. (She even had the umbrella!) But the dressing up didn't stop there. The author/fashion designer had a second ghost costume since she attended multiple events. (Just imagine the "horror" of a repeat...) Meanwhile, Modern Family star Sarah Hyland went to blogger Just Jared's annual Halloween bash as Spinelli from the animated series Recess, complete with candy corn-colored striped tube socks. Click through the gallery below to see more stars in costume!