MacDonald Gargan was a failing private investigator that was turned into the Scorpion with financial help from J. Jonah Jameson. He became the host of the Venom Symbiote and was part of Norman Osborn's Dark Avengers. After it was taken by the US Government, he became the Scorpion once again.
Carmilla Black is the new Scorpion with chemical-based powers. However, she has no connection to the original Scorpion. Her mother genetically engineered her and others called the Wakers. Formerly part of S.H.I.E.L.D., Carmilla's current loyalties are a mystery, but she remains an effective spy.
Current Versions:
Mac Gargan
Carmilla Black