News Kendall Jenner Wore an Emerald String Bikini Top for Her Powerpuff Girl Halloween Costume By Alexandra Whittaker Alexandra Whittaker Instagram Twitter Website Alexandra Whittaker is a news and pop culture editor based in New York City. She studied at the Medill School of Journalism at Northwestern University and at Marquette University, where she freelanced for USA Today, Women's Wear Daily, and ELLE. She currently leads both the news and entertainment teams at Cosmopolitan magazine and previously worked as the news editor of InStyle.com where she spearheaded awards coverage. She enjoys writing and editing news stories, interviewing celebrities, and covering the intricacies of the British royal family. InStyle's editorial guidelines Updated on November 1, 2017 @ 11:45AM Pin Share Tweet Email Kendall Jenner doesn't turn 22 until Nov. 3, but she chose to celebrate her big day a little early so she could wear a Halloween costume during the festivities and, honestly, we don't blame her. The model threw a Halloween-slash-birthday bash on Tuesday, and she picked the best outfit to wear while doing it. Throwing it back to the '90s, Jenner by dressed as a grown-up modern-day Buttercup from the Powerpuff Girls. Her costume was complete with a bright green bra and blunt black bangs with green accents, and she looked ready to fight crime (or party, whichever comes first). Photographer Group / Splash News But what's a Powerpuff Girl without her sisters? Jenner's actual sisters opted for different Halloween costumes like Selena for Kim and an angel for Kylie, for starters. To see more celebrity Halloween looks, including what the other KarJenner sisters wore, be sure to check out this gallery. While Jenner's actual sisters weren't part of her group costume, she was joined by gal pal Hailey Baldwin as Bubbles, and the two put a new spin on an old cartoon look. Photographer Group / Splash News As for the third Powerpuff Girl Blossom? We aren't too sure who played the part, but if she dressed anything like Kendall and Hailey, we bet her look was a win too. What a way to ring in year 22 with a bang, Kendall!