She has spiky pink shoulder-length hair fashioned into pigtails with red hair bands. She also has hearts for pupils that is orange-red, and her right eye usually hangs out of its socket. The upper right side of her head is gone, exposing her brain, part of which trails down past her face. Cosmo doesn't exhibit many emotions aside from her usual smiling, happy-go-lucky attitude. She doesn't speak except for repeating the word "Halloween"