The Preserver is an enemy of Superman who tries to capture him and the last remaining survivors of all types of extinct species and lost civilizations throughout the cosmos against their will in the Superman series. This alien has an unknown past that led him to become a collector. He travelled around the universe and collected the last of all different creatures and forgotten cultures from other worlds.
During his search of Superman who is the last Kryptonian alive, he made a deal with Lobo in exchange for money to lure him to his base. Preserver managed to capture Superman but later betray Lobo since he is the last Czarnian. He also studied the weaknesses of the specimens such as Superman's weakness to red sun light based the Preserver's study of planet Krypton.
Superman and Lobo escaped and the Preserver sends his security droids to neutralize them and send them back to their cells. They managed to subdue the droids and continued their escape. Lobo's rival Gnaww arrives and the Preserver aids him to capture Superman and Lobo. After Lobo defeated some security droids, the Preserver orders him to go back to his habitat. Lobo refuses so the Preserver transforms into a more stronger state and fight him. The Preserver fight Lobo and later Superman. He also provides difficulty to them. Lobo manged to unlock the hatch doors releasing the Preserver into space.
The Preserver was referrenced again in another episode of Superman: The Animated Series.