The woman who would become Poison was a first-year student at the University of Havana in the nation of Cuba. There she met and became romantically involved with a member of the military staff of the Soviet embassy. When she became pregnant, however, the man – known so far only as “Vassily” -abruptly terminated their relationship and issued a statement claiming Cecilia was a prostitute seeking diplomatic favors. Werther to not Vassily was coerced into making this claim is not yet known. However as a result of this statement, Cecilia was imprisoned. There, due to the extremely unsanitary conditions, she soon became ill with an unspecified disease. The Cuban authorities sent Cecilia and other undesirables” to the United States. Cecilia, but went to live in a refugee camp in Florida.
There she gave birth to her son, Carlos, but her disease worsened. Then a mysterious other-dimensional entity which called itself “Ylandris” appeared to Cecilia as she lay dying. Ylandris claimed to have appeared on Earth accidentally and that she would soon die as a result of her bodily form being dispersed in Earth's atmosphere. Ylandris would provide Cecilia's beleaguered immune system with the strength needed to fight off her illness, while Cecilia's body would serve as a containment vessel for Ylandris's life force.
This desperate plan worked and Cecilia recovered from her illness, now with the life energy and consciousness of Ylandris within her. However, she found herself driven, partly by the mind Ylandris (who was a warrior on her home world) and partly be her own desire to strike back for the wrongs that had been done to her, if only symbolically combating evildoers, she called “The Destroyers of the Heart”. Cecilia adopted the identity of Poison, that supposedly being the English name of “Ylandris”, and embarked on a career a an occasional vigilante with the aid of the superhuman abilities of the being with her.
Sometime later Ylandris successfully left Cecilia's body and returned to her home dimension through the Nexus of All Realities located in the Florida Everglades. However, Cecilia retained her superhuman powers, and continues her fight against evil as Poison. Recently, Poison was among a number of heroes and villains capture and killed by the “Hand” and Hydra to create an army of superhuman solider. Poison appeared to be killed by Wolverine during the Hydra's attack on the S.H.I.E.L.D Helicarrier. Given her power, it is unclear if she is truly dead.
- Height: 5'6"
- Weight: 115lbs.
- Eyes: Brown
- Hair: Brown
The full range of the mutagenic changes wrought on Celcilla's body by the presence of the alien being Ylandris is still unknown. Thus far, Poison has demonstrated superhuman strength, exceptional atletic abilitiy, as well as the power to levitate and teleport herself and others. She can also psionically alter the flesh of others to make them sick, injured and diseased.
Web of Spider-Man Annual #4, Spider-Man #64