Zypto was the father of Superman's pet dog Krypto. Zypto lived in Zaro City, where a lightning storm struck all of the canines and energized a virus in their bodies. City officials declared that all dogs in Zaro City be euthanized in order to keep the virus from spreading. The concerned father of Valla, the young girl who was Zypto's owner, put the dog in a small jet-powered aircraft so that he might escape extermination. The jet-craft crashed into the aviary of experimental biologist Professor Zak-Zil, just as Zil was completing a serum designed to allow mammalians to grow wings and fly. Zak-Zil fed the serum to Zypto. As a result, Zypto immediately grew a pair of full-sized white wings. Zypto later returned to Valla, but was intercepted by the Dog-Exterminator Squad of Zaro City. Valla's father witnessed this and advised that the Squad had no authority over "avia-dogs". the Squad released Zypto into the custody of Valla's father. Later, Valla's father was experimenting with space-jewels he had found in a meteor. The space-jewels gave off an invisible, radioactive gas which would have killed Valla and her father. Zypto saved them, sacrificing his magnificent wings in the process.
- This version of Zypto (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 Zypto (Earth-One)
- 1 Images featuring Zypto (Earth-One)
- 1 Quotations by or about Zypto (Earth-One)
- Character Gallery: Zypto (Earth-One)