History
The man known as Ivan Renz was a employee of Stark Industries, alongside his mentor, Minka Tross and the couple, Richard and Mary Parker. As a group, they developed radiobiology tech known as “The Key”, a restorative, gene-bending device that could potentially bring people back to life. But the experiments failed, and a revived test subject killed Minka. Tony Stark, not wanting to play god, dismantled the unit. Then S.H.I.E.L.D. showed up looking to weaponize their discovery. The implosion of their careers prompted Richard and Mary to destroy all remaining evidence of the The Key, except for one test subject, a genetically enhanced spider. Ivan eventually became the supervillain known as Cadaverous. He and his minions nearly ravaged New York City in a confrontation against Spider-Man, during which the villain appeared to plead the hero for help, since he needed Peter's radioactive blood to recreate his experiment in order to revive his old mentor.[2] When Spider-Man's wife Mary Jane Watson tried to help him out, they were attacked by the invading forces. Cadaverous' minions swarmed Spider-Man, leaving him powerless to stop Cadaverous from impaling Mary Jane and throwing her off the bridge where the fight was taking place. Spider-Man appeared to have repelled the villain afterwards.
Twelve years later, Cadaverous started plotting his next plan in front of a woman in a containment unit.[3]