Hailey Bieber as Pebbles Flinstone Hailey Bieber opted for a Pebbles Flintstone costume, reimagining the kid's cartoon character as an adult. In a latex top and miniskirt, complete with a red bob wig, she attended Vas Morgan and Michael Braun's Halloween Party on 28 Oct. in LA. Image Source: Getty / Rachpoot/Bauer-Griffin