Alopex is an athletically-built mutant arctic fox with snow-white fur, amber eyes, blue war paint around her eyes, and a bushy tail. She wears torn black ninja clothing, fingerless gloves, knee-high stockings, a fang necklace, and sometimes a green bandanna during vigilante work. Born as a normal fox near Fairbanks, Alaska, Alopex was feared as a deadly hunter until scientists captured her and transformed her into a human-like mutant with human intelligence. She later became the apprentice of the Shredder and a ruthless Foot Clan assassin, killing without hesitation for her master. After leaving the Foot Clan, Alopex changed into a calmer, more sympathetic vigilante with a sarcastic streak. Though she often teases her friends, she deeply cares for them and becomes hard on herself when she fails to protect others. She is especially enraged when children under her care are harmed. Alopex is the leader of the Claw Clan, a master of Ninjitsu, and the owner of a shelter in Mutant Town. She is also close friends with Leonardo, Donatello, Raphael, Michelangelo, and Jennika.