Doctor Franz was a neighborhood pharmacist and inventor who had befriended rookie police officer Dan Garret. Sensing that Garret was a virtuous man, he entrusted him with his two greatest inventions: A bulletproof chain-mail costume with a silk fiber overlay and Vitamin 2-X which bequeathed anyone who imbibed it with enhanced physical attributes. Armed with these two inventions, Dan Garret became the costumed adventurer known as the Blue Beetle.
- This version of Doctor Franz, including all history and corresponding appearances, was erased from existence following the collapse of the original Multiverse in the 1985–86 Crisis on Infinite Earths limited series. Even though versions of the character may have since appeared, this information does not apply to those versions.
- 25 Appearances of Doctor Franz (Earth-Fox)
- 1 Images featuring Doctor Franz (Earth-Fox)
- Quotations by or about Doctor Franz (Earth-Fox)
- Character Gallery: Doctor Franz (Earth-Fox)