His professional debut was in 1991, writing and painting Innovation Comic's
Rocketman: King of the Rocketmen. This was followed by a run on the adaptation of
Anne Rice's
Interview with the Vampire, also from Innovation, for which he provided artwork and a number of cover illustrations. Moeller moved to
Dark Horse Comics in 1994, writing and painting the first of his
Iron Empires graphic novels (at that time called
Shadow Empires)
Faith Conquers, as well as the short story "The Passage" in
Dark Horse Presents #79-81. He illustrated
Andrew Vachss' short story "Treatment", included in Vachss' 2002 graphics-adapted collection
Hard Looks. He also did
James Bond covers, a number of
Star Wars covers, and a "pop-up"
Star Wars book called
Battle of the Bounty-Hunters. In 1998, Moeller wrote and painted his second
Iron Empires graphic novel, ''
Sheva's War'', for the short-lived science fiction imprint of
DC Comics,
Helix. He made a run of covers for DC's
Batman monthly comic book
Shadow of the Bat. In 2000, he wrote and painted the graphic novel
JLA: A League of One. He did an extended run of covers for the
Vertigo monthly comic book
Lucifer. In 2005, he wrote and painted the graphic novel
JLA Classified: Cold Steel. ==Gaming career==