- "Fifth Dimensional life forms possess the ability to warp our reality to their own whims. Abilities that would appear, to all intents and purposes, to be magic."
- —J'onn J'onzz[src]
The Fifth Dimension is a plane of existence in the multiverse populated by lifeforms known as the "Fifth Dimensional imps", able to alter reality at their whim. One of such imps, Mxyzptlk, invaded the universe of Earth-38 in an attempt to marry Supergirl.
Although a part of the multiverse, the Fifth Dimension is not referred by the typical naming of "Earth Number", and is seen as something entirely alien to Earth and Earthen reality as whole. This allows its denizens to alter reality while staying present in a universe such as Earth-38. The powers that beings native to this dimension hold have been interpreted and labeled as magic. Throughout history, such beings have been known under many names, such as genies, djinn, leprechauns and imps.
The Fifth Dimension has authorities and a court system that does not appreciate its citizens interfering in the lives of lower dimensional beings.
Before the catastrophe that destroyed the sister planets of Krypton and Daxam, the Daxamites had knowledge of the Fifth Dimensional imps, coming in contact with those creatures. While, at Mon-El's admission, they knew how to party, the imps were considered too dangerous due to their immense reality-warping capabilities, resulting in a "no-tolerance policy" for their shenanigans, forcing them to seek weapons to stop the imps' powers, in addition to killing them upon sight and identification. Somehow, despite Krypton's proximity to Daxam, the former's inhabitants would appear relatively unaware of any contact that happened between Daxamites and imps all the way to their planet's destruction. The denizens of Mars were also implied to have had contact with the Fifth Dimension, as J'onn J'onzz, through Zook, had knowledge of their powers and activities.
A Fifth Dimensional intruder, Mxyzptlk, watched Kara Zor-El of Earth-38 for some time, eventually becoming infatuated with her. Appearing on Earth, Mxyzptlk started a disastrous campaign to woo Kara with his reality-altering powers, alternating between surrounding her with adoration and flowers, trying to create a crisis to solve for them together, and trying to fight Mon-El over Kara's heart. Despite the imp's overwhelming powers, Kara managed to trick him, forcing the imp to spell his name backwards at the threat of her suicide in the inescapable Fortress of Solitude, the choice of free will that the imp could not prevent with his powers. A lover scorned, the mad imp dissipated to his dimension, angry at Kara for rejecting and banishing him.
The authorities and court system of the Fifth Dimension punished Myxzptlk for his interference in the lives of lower dimensional beings. As his penance, he sought to improve Kara's life; she chose to see different timelines in which she told Lena Luthor her secret earlier than she had. Eventually, they learn, among other things, that Fifth Dimensional energy can be dampened and nullified.
- Brpxz (status unknown)
- Nyxlygsptlnz (relocated to the Phantom Zone)
- Nyxlygsptlnz's brother (deceased)
Behind the scenes
- In the DC comics, the Fifth Dimension is home not only to Mr. Mxyzptlk, but to other reality-warping imps, such as Bat-Mite and Qwsp. Fifth Dimension contains worlds such as Zrfff, along with cities built by reality-warpers, such as Mxypolis, patterned by Mr. Mxyzptlk and Bat-Mite and built in the likeness of Earth's Metropolis.