Jennifer Garner and Ben Affleck took their kids trick-or-treating in Malibu last night. The whole family wore costumes from The Wizard of Oz with Jennifer in a princess look, Ben wearing a Tin Man outfit, Violet as Dorothy, and Seraphina in scarecrow gear. They met up with pals Tobey Maguire and Jennifer Meyer, whose daughter Ruby was also dressed up as Dorothy. The kids gathered candy, rode on a wooden train, and checked out farm animals during the neighborhood Halloween party, which was just one of many. Rihanna threw a bash in LA while Gwen Stefani attended a party in London and other stars got festive in NYC, despite the storm — check out all the celebrities in costume!