Zaltar was a Kryptonian man trapped in the Phantom Zone. He lived there for many years in quiet misery, until he met Kara Zor-El (now called Supergirl), who had been sentenced there by Selena. Supergirl rallied his help in escaping the Zone, and together the two nearly made it to the top before Zaltar was killed by tidal forces inside the zone. Thus far, he has only appeared in the movie Supergirl.