Zak-Kul was a Kryptonian scientist and criminal who lived in the bottled city of Kandor. He is known for the development of an enlarging ray called Illium 349, which allowed Kandorians to grow in size and leave the city. When Lois Lane accidentally opened the bottled city, Zak-Kul used his ray and escaped. He was later captured by Superman and returned to Kandor. Zak-Kul's Illium 349 was later used to enable Van-Zee to increase in size so that he could leave the city.
- This version of Zak-Kul (Earth-One), 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.
- 1 Appearances of Zak-Kul (Earth-One)
- 2 Images featuring Zak-Kul (Earth-One)
- Quotations by or about Zak-Kul (Earth-One)
- Character Gallery: Zak-Kul (Earth-One)