Doll Man was, according to Wikipedia, created by legendary Golden Age comics writer and scholar Will Eisner. Doll Man had the ability to shrink himself to a miniature height of 6 inches. The original Doll Man comics ran from 1941 to 1953.https://en.wikipedia.org/wiki/Doll_Man
The character is currently owned by DC comics and reappears periodically. In DC canon, the original Doll Man eventually went mad as a side effect of the shrinking and is currently incarcerated in an insane asylum.
Insane asylums still exist in the world of comic books.
The current Doll Man is stuck in his miniature form as a result of… some kind of complicated DC comic book nonsense… which presents challenges in his relationship with his girlfriend.
Short answer: Yup, Doll Man is a real Golden Age comic book character and was reasonably popular through the 1940s.
Fun fact: Doll Man shares a first name (with different spelling) with AMMO’s own BlondeActionMan.