Simonson is most known for his work on Thor, which he wrote and illustrated for nine years, during which he created the character Beta Ray Bill and Malekith the AccursedAmong others.He has also worked on other Marvel titles such as X-Factor and Fantastic Four, on DC Comics books including DETECTIVE COMICS, Manhunter, Metal Men and Orion, and on licensed properties such as Star Wars, Alien, Battlestar Galactica and Robocop vs. Terminator.In addition to his work for both Marvel and DC, Simonson has also generated a considerable body of creator-owned work, like Star-Slammers and Ragnarok.