Doctor Vicktor (voiced by Michael Dorn) is a Transylvanian from Anur Transyl (an alien resembling Frankenstein's monster) who works at NASA, disguised as a human scientist as a means to hijack a space shuttle. He is intelligent, and working for Zs'Skayr; his immediate plan was to resurrect his master, whose ultimate plan was to prevent the sun's light from reaching the earth using various satellites (therefore meaning that Zs'Skayr would be at full power all of the time). He is not treated with respect after Zs'Skayr is resurrected. After he asks why they need Ben, Zs'Skayr takes control of his body and throws him around. He serves as the unofficial leader of the three horror-themed aliens. The purple lightning that the previous two horror aliens appeared in was generated by a teleportation machine that he uses. His name is derived from the name of Victor Frankenstein from the Mary Shelley novel. His first appearance is in "The Return", where he succeeds in reviving Zs'Skayr. In the next episode "Be Afraid of the Dark", Ben fights Doctor Vicktor and Zs'Skayr on Earth. Ben accidentally gains use of Doctor Vicktor's form when Vicktor finds Ben and grabs him by the wrist, unintentionally adding his DNA to the Omnitrix. Vicktor essentially defeats himself near the end of the episode. In an attempt to teleport Ben to an unspecified location, he and the mummy alien are tossed into the portal he created.

Ben 10: Protector of Earth features "Vicktors" as enemies on Zs'Skayr's planet.