Ken From Greta Gerwig's "Barbie" Being Ken from Greta Gerwig's "Barbie" movie is the men's DIY Halloween costume you never predicted to be so easy. Opt for a quirky-printed button-down shirt with retro vibes, and finish the outfit with a pair of chinos, accessorising with a pink bandana tied around your neck. You can always add platinum hair to really drive home the point.