Tomnu hailed from the time of ancient Krypton. Very little is known of him save that he was the son of Rugad, the grandson of Feln and the father of Erok. Erok was the first Kryptonian to adopt a House name and became the first actual member of the legendary House of El.
- This version of Tomnu (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.
- Tomnu has never made an actual in-continuity appearance and has only been referenced by other characters. A family tree provided in Krypton Chronicles #3 establishes him as one of the first recorded members of the House of El.
- Appearances of Tomnu (Earth-One)
- 1 Images featuring Tomnu (Earth-One)
- Quotations by or about Tomnu (Earth-One)
- Character Gallery: Tomnu (Earth-One)