Superhero Wiki
5th Dimension

Residents
Mr. Mxyzptlk, Bat-Mite, Ms. Gsptlsnz
First Appearance
It was referenced in Superman Vol 1 (Vol. 1) #30 (September, 1944) and was notably shown in JLA #30 (though it is not clear if that is the first visual appearance of the 5th Dimension)
Location
Higher Dimension in the DC Universe
Points of Interest
Mxypolis, Zrfff

The 5th Dimension is a dimension in the DC Universe and the home to interdimensional imps, such as Mr. Mxyzptlk and Bat-Mite, as well as genies, such as Thunderbolt.

History[]

The exact history of the 5th Dimension is hard to know, largely because of the chaotic and bizarre nature of it's reality.  It is hinted that while the dimensions 1-4 are height, width, depth, and time, the fifth dimension might be imagination, as suggested to 5th dimensional resident Bat-Mite while in conversation with Batman, (who may or may not have been a hallucination at the time).

The reality of the 5th Dimension does not resemble our own, meaning what is recorded about its history may be taken with a grain of salt.  What is known is that the beings of that dimension have the ability to warp reality through a form of super science beyond the comprehension of the beings of lower dimensions.

It is home to various "imps" and "genies" and magical creatures seemingly capable of anything their imaginations can conjure.

Mr. Mxyzptlk and Bit-Mite[]

At one point, one imp, the mischievous Mr. Mxyzptlk arrived outside of the 5th Dimension to Earth to plague Earth's greatest living hero, Superman, only to be tricked by him and sent home.  From then on Mr. Mxyzptlk, about every 3 months would return to Earth, concocting a new plan to defeat Superman. Other notable imps included Bat-Mite, an imp so obsessed with Batman he emulated him and often caused trouble to make his adventures more exciting. Other 5th Dimensional imps would also come to visit Earth, often with the intent of being friends or foes to Earth's heroes.

Notably, the inhabitants of the 5th Dimension seem away of their own fictionalness at times, breaking the fourth wall in ways only a few other characters, like Ambush Bug, are capable of.