The Serpent in the Subway was a mysterious underground monster that attacked Paris, France. The Suicide Squad were visiting on vacation, and they tried to subdue the beast. It chased them through the underground tunnels and escaped into the city. Rick Flag noticed that it could breathe both in water and on land, so he tried to suffocate it. This was difficult and the monster began attacking the Eiffel Tower. They manufactured a giant plastic bag and used it smother the serpent to death.
- This version of Serpent in the Subway (Earth-One), including all history and corresponding appearances, was initially erased from existence following the collapse of the original Multiverse in the 1985–86 Crisis on Infinite Earths limited series. However the ending of Convergence retroactively prevented that collapse, saving all the alternate realities, though in an "evolved" form. Even though versions of the character may have since appeared, this information does not apply to those versions.
- 1 Appearances of Serpent in the Subway (Earth-One)
- 3 Images featuring Serpent in the Subway (Earth-One)
- Quotations by or about Serpent in the Subway (Earth-One)
- Character Gallery: Serpent in the Subway (Earth-One)