What's up, Buttercup? Kendall Jenner enlisted the help of her pals Hailey Baldwin and Justine Skye for her latest Halloween costume; the three dressed up as sexy versions of the Powerpuff Girls at a party they threw at the West Hollywood restaurant and lounge Delilah on Tuesday. Jenner was Powerpuff Girl Buttercup, one of the original three. She wore a short, black wig with a green streak, a bright green bikini top under a black semi-sheer top, paired with a green painted leather jacket, a black shredded mini skirt, and thigh-high black fishnet stockings and leather boots. Baldwin was blonde Bubbles, also one of the original three Powerpuff Girls....