Yelena is a Russian demigod daughter of Khava Dumin and the Greek god of war Ares. She is 6'4 with long brown hair that often seems black in low-light settings, brown eyes and a quite muscular body covered in scars from head to toe. She is deaf and wears hearing aids.

She has a twin brother named Mikhail, and several younger siblings. After leaving camp half-blood and going out into the mortal world, her and Mikhail decided to become police officers and are now their current occupation.