The creature is never given a name in the comic itself. The name "Doppelgänger Demon" comes from the fact that the creature is a demon, and that it at first resembles Godzilla before transforming into its true form.
When in his disguised form, the Doppelgänger Demon closely resembles Godzilla, except for the fact that they are covered in multiple scars and wounds, and appear to be missing one of their eyes. Once investigated or nearing their prey, the Doppelgänger Demon will split its skin open and reveal its true form, a beast with massive jaws and a multitude of sharp-tipped tendrils. However, in its true form, the Doppelgänger Demon keeps Godzilla's dorsal fins.
The Doppelgänger Demon encounters Godzilla in Hell. Godzilla, after wading through a storm cloud composed of damned souls, discovers what appears to be another Godzilla in the eye of the storm. However, the Godzilla he sees stares off vacantly into the distance. Upon further inspection, the demon takes its true form, and catches Godzilla off guard. The demon gradually transforms over time, opening up more mouths, until finally what was once the Godzilla facade's chest opens up and he attempts to devour Godzilla whole. The decision turns out to be a poor one and Godzilla does the same thing to the demon that he did to Orga, blowing the monster to pieces from the inside out.
- The Doppelgänger Demon's behavior in attempting to consume its prey using its massive jaws may be a nod to Orga.
- The demon's true form is also a possible reference to the alien creature from John Carpenter's The Thing.