Carmilla Black is a genetically engineered human, created by Advanced Idea Mechanics (A.I.M.). Though A.I.M. Scientist Supreme Monica Rapuccini considers her a daughter, she grew up with adoptive parents, who were also agents of A.I.M., never knowing of her or their involvement with the organization. Carmilla considered herself a normal teen until her latent powers manifested on the night of her prom. Her mutated arm, which she has taken to calling her stinger, discharged a highly concentrated dosage of toxins, killing her boyfriend. Scared of the social and legal backlash she would suffer, she fled her small home town. For years, She lived on the streets, surviving however she could, constantly roaming from place to place. When she learned her adoptive parents had been murdered, she returned home.
She came to suspect that S.H.I.E.L.D. may have had her parents killed, and found a birth certificate suggesting she was a princess of the Madripoor Royal Family. After she was captured by S.H.I.E.L.D., she learned that her parents were actually A.I.M. agents, and she herself became an agent of S.H.I.E.L.D. under the code name Scorpion.
Following information leading to her biological mother, Carmilla learned her mother was 'Scientist Supreme' of A.I.M., Monica Rapuccini. Scorpion infiltrated the organization, learning that she was engineered to survive disease and even nuclear fallout, and that there were others like her.
These teens were designed to survive any situation they may encounter, from a global plague intended to collapse industrial society to nuclear fallout. While the other teens were chemically-induced to be completely loyal to A.I.M., Scorpion discovered the mutation which gave her stinger also made her immune. Carmilla lost her cover in the organization when she stopped an assassination attempt on the Vice President.
Recently, Carmilla and her S.H.I.E.L.D. handler, agent Derek Khanata, had been sent to New York under orders to track down and capture the Uni-Power before it could fall into the hands of the terrorist organization A.I.M., watching over the spot where a Captain Universe empowered Daredevil fought four Class Three A.I.M. Commandos. Scorpion and Khanata waited to see if A.I.M. would find anything. A group of kids interrupted the A.I.M. Agents work and were nearly killed until X-23 stepped in. The A.I.M. Commandos who fought Daredevil before began to assault X-23 when she became Captain Universe. Scorpion entered the fray helped X-23/Captain Universe defeat the Commandos. Afterwards X-23 began to search for a hidden base. Scorpion joined her so that she could obtain and capture the Uni-Power and get the information on it from A.I.M.; however, X-23 convinced Scorpion to see the light and let the Uni-Power go. X-23 took the Uni-Power to a safe hiding place while Scorpion captured an A.I.M. scientist back to S.H.I.E.L.D. for interrogation.
There exists a possibility that Bruce Banner (the Hulk) is her biological father, but this speculation has not been confirmed.