Alopex was born an ordinary arctic fox outside of Fairbanks, Alaska. She proved herself deadly from an early age, serving as her pack's main hunter. She was both feared and respected by all other creatures in the area, save for a polar bear - the only being Alopex feared.
This life continued until she was captured by a group of scientists attempting an experiment to bring other animals to human-level intelligence. In Alopex's case, the experiment was a success, first granting her human intelligence and then a human-like body. She was rescued from the laboratory by the Foot Clan's leader, Shredder, for whom she became a loyal spy and assassin.
One of her first missions consisted of playing a damsel in distress to Raphael so that she could find the Ninja Turtles' lair. However, Raphael quickly saw through her act and she managed to escape. Alopex clashed with Raphael a second time when he and his brothers rescued Master Splinter from imprisonment at the hands of the Foot Clan.
Alopex played a major part in Shredder's ultimately unsuccessful plan to retrieve the Ashi no Himitsu, a tome containing the secrets of the original Foot Clan.
Although Alopex served the Foot faithfully, she still had some attachment to her old home and family. Seemingly aware of this, Shredder sent her back to Fairbanks - while he had the forest burned down as a test of loyalty. Alopex attacked Shredder, although she quickly surrendered and professed her ultimate loyalty to the Foot Clan. However, comparing Shredder to the bear that had been the bane of her existence in her earlier life, she secretly swore that she would one day kill him.
During a fight between Shredder and Master Splinter, Alopex finally attacked her master. She did not succeed in killing him, however, and was stopped by Karai - who up to that point had considered Alopex an ally and friend - with an arrow in the chest.
Alopex was created by Teenage Mutant Ninja Turtles creator Kevin Eastman, marking the first time he created a new TMNT character in over 15 years.