Outside of the comics, they appeared in the Legion of Super-Heroes animated series and cameoed in the animated film Green Lantern: Emerald Knights.
As Guggenheim noted, the Dominators, a technologically advanced alien race, originally started out as foes of the Legion of Super-Heroes, who were teased during Supergirl Season 1.
As seen in the picture above, they’re one of the uglier comic book alien races out there, but fortunately, it sounds like The CW won’t waste any expense in making their TV counterparts look similar to how Spawn creator Todd McFarlane designed them in the late 1980s.
However, the Dominators’ big moment to shine came in the Invasion! event, where they were the driving force behind an Alien Alliance that attacked Earth because they were worried about the growing population of metahumans.