Name: Dolores Winters
Other Names: Delores Winters
First Appearance: Action Comics (vol. 1) #20 (Jan. 1940): "Superman and the Screen Siren"
Number of Appearances: 1
Employer: Colossal Films Studio
Dolores Winters was a famous film actress whose life was saved by Clark Kent while touring a Hollywood studio set. The grateful actress agreed to allow Clark Kent to interview her the next night. But by the time Clark went to her home for the interview, Ms. Winters' brain had been replaced by the brain of Superman's arch-enemy, the Ultra-Humanite.
After Superman realized who he was actually dealing with when confronting Ms. Winters' body, the Ultra-Humanite explained to Superman what had happened. In the Ultra-Humanite's most recent confrontation with Superman, the villain's body apparently died after being hit by a blast from a laser cannon - a blast he had intended for Superman. Superman had thought that the menace of the Ultra-Humanite was ended. But in fact, as he now learned, his assistants had come along and revived his body. His body, which had already been quite elderly and weak, could not last long before dying permanently. So the Ultra-Humanite had his assistants kidnap Dolores Winters and put his body into her healthy young body.
This means that most of what we saw of "Dolores Winters" throughout this story was not actually her. The real Dolores Winters had indeed been saved from an assassin by Clark Kent, and had indeed invited him to interview her the next night. But before they met up again, Dolores Winters had been kidnapped and her mind removed (and thus killed) by Ultra-Humanite's assistants.
The evil criminal mastermind stayed in Dolores Winters' body only temporarily. Before long he came to occupy the body he is best known for, that of a massive albino ape.