This monster bears inexplicable resemblance to "Dread Dragon".
The above is odd because "Dread Dragon" cannot be used for this card's Synchro Summon.
However, their design likenesses might make sense in the guise that the monsters are used by Jack Atlas and Kalin Kessler respectively; these two characters are related in that they both were one part of The Enforcers. Moreover, this monster's more dilapidated appearance may symbolize the more dark and entropic path that Kalin chose in his existence after his time as a Dark Signer.
They are both Level 8 DARKAttribute monsters with have 3000 ATK and require a DARK Attribute Tuner monster to Synchro Summon themselves. The difference, however, is that the non-Tuner monsters used to Synchro Summon "Infernity Doom Dragon" does not have to be Fiend-Type monsters.
There appears to be a portion of its brain revealed in between the various prongs that circulate its head (the small pink matter cluster visible directly above its eyes).
As revealed in the art of "Infernity Barrier", "Infernity Doom Dragon" actually has a perfectly round ridge of "horns", with the brain placed perfectly in the middle - this may imply that the "horns" of "Infernity Doom Dragon" are, in fact, sections of its skull that are opened up, surrounding the brain.
This monster somewhat breaks the theme of many "Infernity" monsters taking after classical American Western themes - cowboys, Native Americans and the like, though some also resemble European knights and demons - but still fits in by way of resembling a daemonic, somewhat twisted interpretation of a usual concept (in this case a dragon), much like the other "Infernity" monsters appear to be twisted, demonic versions of Spaghetti Western stereotypes.
In fact, this is easily one of the most abstract looking dragons in the game, resembling, in equal measures, a classical dragon, an insect, some type of horned biped, and a Xenomorph from the Alien series.