Citizens: Mr Mxyzptlk.
First mentioned in: Supergirl: ‘Mr and Mrs Mxyzptlk’.
Notes: Not much is known about the Fifth Dimension, but from the name we can assume that it is more of a multiversal realm than a single universe or planet. Beings from the dimension have the ability to alter reality on a whim and have wormed their way into Earth’s mythology, in the form of genies, imps and pixies.
Citizens: Time Wraiths, Black Flash, Savitar (formerly), Jay Garrick (currently).
First appeared in: The Flash: ‘Fast Enough’.
Notes: On the one hand, the Speed Force is an energy source from which speedsters draw their power. On the other, it is an extra-dimensional realm all of its own, one which spans time and has existed since the Big Bang. It has enforcers known as the Time Wraiths – and recently Black Flash – which punish speedsters who meddle with time. It is also possible to imprison a speedster within the Speed Force.
Citizens: Satan, Nergal, Astra Logue, Mnemoth, Lamashtu, John Constantine (currently).
First appeared in: Constantine: ‘Non Est Asylum’.
Notes: When the sorcerer John Constantine attempted to exorcise a demon from the human child Astra Logue, it went tragically wrong and Astra herself was sent to Hell – an inter-dimensional realm inhabited by demons and the souls of the damned. Oliver Queen later stated that John Constantine was himself trapped in hell for unknown reasons.