Dr. Double X
energy duplicate of Dr. Simon Ecks
- Also known as Doctor Double X
Appearances
- World's Finest Comics #276 — 1982-02-00
- Who's Who: The Definitive Directory of the DC Universe #6 — 1985-08-00
- Crisis on Infinite Earths #10 — 1986-01-00
- DCU: Legacies #6 — 2010-12-00
- DC Universe: Legacies #[nn] — 2011-10-00
- DC Universe: Legacies #[nn] — 2012-07-00
- Batman #17 — 2017-04-00
- Batman #3 — 2017-10-00
- Batman: Rebirth Deluxe Edition #2 — 2018-08-00
- Batman #75 — 2019-09-00
- Batman by Tom King #1 — 2025-02-00