Thirteen is a reaper with pale skin and long, colorful hair parted in the middle. Her hair starts pink at the roots and turns purple and blue further down. Her eyebrows are also blue. Her eyes are vaguely reptilian in appearance due to her vertical pupils. They are lime green with a pink gradient. Thirteen is also visibly wearing makeup: eye shadow that matches the colors of her hair and red lip gloss. On her hands, she wears yellow nail polish.