Doom's demons changed through games and some variations are more unique than others.
It's a fun thing to look at, specially because it makes the series bigger than it seems at first and even makes one wonder what would ever come next.
The point of this post is to see which versions of each demon from the Doom 2 roster are the most unique, either by visual design or gameplay.

Zombieman:

He went from "zombie that knows how to use bullet based guns" to "body horror mutated soldier with flesh mixing up armor and plasma rifle", so probably 2016.
Eternal brings back the classic green hair look but retains the plasma projectile role, so modern Doom deviates from those walking corpses that were buddies with Doomguy.
Besides replacing the bullets with projectiles, they also have a charged plasma ball that stops in the air before exploding.
They fit the fact that in lore, UAC soldiers use Plasma Rifles though it seems to not be as "literal" since they still have a unique plasma rifle from that of the player and those ARC guys.
(Not like anyone was expecting id to make a "Plasmagunner class" type of enemy like something out of Realm667, specially with how resource management works in new Doom too).

Shotgunner:

Similar deal as above, with the 2016 possessed security even having an energy shield, that Eternal then makes it vulnerable to the player's Plasma.
Because the D3 zombies are essentially SWAT guys in Mars and they do have shields or the ability to roll but they're still an extension to the classic zombieman concept.
Honorable mention: Eternal concept art showing possessed soldiers as literal demons and with much more different designs, nothing to do with humans.
If you think about it, the Marauders are the new "former humans" since the Sentinel were Doomguy's new buddies and they even have an SSG.
(Meanwhile, Immora soldiers carry the Reaper from 2016 but are still a variation of Possessed Soldiers, so the Reaper doesn't have the actual mechanic it originally had.
(And then the Dark Lord is only Doomguy-like from the face and not armor nor moveset of weapons.
(Meanwhile, Doom 3 turned the marine's boss into a tank monster with the BFG 9000).

Chaingunner:

Eternal TAG2 makes him another energy shield zombie with an attached cannon that shoots energy bullets (Also, helmet) but D3 might take the cake in the visual department for that unique blue skin zombie look, whose melee relative has a tentacle arm.
Honorable mention: Those "I SMELL FEAR" lines they had in the beta version, that Trent Reznor apparently worked for.
They had no presence in 2016 but you can see Hellrazers filling their role back then.

Imp:

D3 is the one that lacks spikes and has multiple eyes like an insect.
Mechanically? Honestly, the modern ones don't even deviate from the basic role that much, even if you argue over the arcing physics of the fireballs, charged fireballs or their mobility and hanging on some walls, i guess.
Nightmare Imps and Prowlers don't really count because they're seperate but relative species, though i think one Imp variant in D2RPG had a burning fireball ability that predates the cursed fireball from Cursed Prowlers.

Pinky:

D3's Pinky is notorious for having the most unique design, like a monster born to suffer.
Mechanically, 2016/Eternal have a charge attack and use their chitin shield to protect their front.
Meanwhile, the cancelled D4 could have very different designs if those Wayne Barlowe pieces are anything to go with.

Spectre:

Eternal makes them resist lock on stuff and 2016/Eternal give it extra health to compensate for lack of the shield mechanism.
D64 made it green and makes them transparent when they're active, then visible when they die.
Meanwhile GBA Doom 2 gave them a bright filter and then there's the higher health PS1 Nightmare Spectre.
Oh and the BREW version of Doom RPG makes the Belphegor a Spectre instead of blue colored in the other versions.
Honestly, not much happens with these.
2016 MP also made the Pinky switch to a Spectre, i recall.

Lost Soul:

D3 had the most unique design because it's a modified human head, though D64 and 2016 still give it bits of flesh, making Classic the pure boney skull.
Mechanically, 2016 makes it a walking rocket by making it explode literally.
D3 and 64 mostly give it AI and/or speed/health differences.
Then D3 RoE had the Forgotten Ones, who look in line with the classic LS's.
Honorable mention: The alpha design where it looked metallic and was hitscan because its attack was described as "corrupting the mind"; I think 2016 also had concept art of cybernetic Lost Souls, some kinda resembing the D3 Berserk pickup.

Cacodemon:

D3 for its unique design (Like an homage to Duke's Octobrain and apparently, was supposed to spew Lost Souls during development), though Classic Caco is the one with weird "hair" underneath whereas 3 gives it a hand, 64 gives it arms and 2016 gave it awkward limbs.
Mechanically, 2016 gave it a vision blur attack, Eternal gives it a projectile barrage and charge and D3 made the projectiles explosive.
Also, 2016 multiplayer gives it a stretchy tongue.

Pain Elemental:

D64 for its 2 mouthed, freaky design, that can even spawn 2 souls at once and ruin that "soul blocking" strategy.
Mechanically, the Eternal PE has a very unique way of handling its souls due to how different the gameplay format is, so the Lost Souls die when their PE dies, instead of being independent or even summoned when a PE dies.

Hellknight:

Used to be a Baron recolor but D3 gave it a design that technically became standard, even though 2016 made it eyeless and Eternal gave it 2 eyes when the D3 one is special because of its weirdly unique, red eye sockets.
(Also, D3 had a "Hell native" version).
Mechanically? 2016 made it a melee brute and no longer a projectile based enemy.
Honorable mention: Eternal's Gladiator for being based off the classic HK look but still having its own unique design elements, while the main HK is the way he is.
Also, RoE's Bruiser is kind of like a cybernetic HK when you think about it.
Oh i almost forgot about the Dreadknight.

Baron of Hell:

2016 made it part of the chitin design family and changed the face, blood color and legs but it's still an angry minotaur.
Though Eternal gave it a fire/lava theme like it was a sub species/variant, so Eternal Baron takes the cake here for stand out.
(Meanwhile, the D3 Birdman could have been a Baron, but i've seen concept art of a D3 Baron with weird unique horns and flesh things coming out of the eyes like tears).
Mechanically, 2016 and Eternal differ from the "Imp with more numbers" role by making it stronger and perform a strong slam attack.
Was thinking of mentioning the TAG2 Armored Baron but like with Prowlers for Imps, he may not really count.
Wonder how many people think that Eternal's Baron was inspired by those fan designs in some mods.

Revenant:

D3 is the most unique one due to features like the transparent body and blue glow in eyes.
Mechanically, 2016/Eternal gave it a rocket barrage and jetpack, even if the classic homing missile logic isn't there.
Honorable mention: Doom Eternal's Plasma Powered Revenant, which looks like it could have been a new enemy.
Cancelled Doom 4.10 also has concept art of a Revenant with metal on its head and fungi across its armor and rocket launchers.
I think in D1RPG, Revenants exploded upon death.

Mancubus:

2016 is a chittin armored, cyclop monster which contrasts the other tech cybernetic Mancubi and is why its acid spewing brother in 2016 is named CYBER-Mancubus.
(Also, no exposed nipples).
Mechanically? D3 Manc already dropped the classic fireball firing pattern but 2016/Eternal add in a bunch of new moves like a flamethrower and slam attack.
Then there's the destructible cannons and BattleMode's smoke bomb.

Arachnotron:

D64 makes it more bug-like with 6 legs and no arms, along with a more brain-y body and double turret.
Eternal makes it inspired by 2016 SMM with the turret as a weak point and blue blood.
Mechanically? D64 also doesn't have a basic projectile sentry attack but 2 plasma balls at once isn't as impressive as Eternal's version throwing grenades and (Though kinda scripted and underused) attachment to ceilings.
Honorable mention: D3 concept art of a spiderbrain demon with a metallic skull on the front (Appears in the D3 Phobos mod).

Arch-vile:

Eternal is the most visually unique one because of its chitin/spiky theme, but also because D3 was just a blander version of the Classic, since it's not as skeleton skinny and has no face tubes.
(In an alt timeline, the D3 Archie could have used the D3 Vulgar model and D64 could have had its own spin on this monster, even if that HR Giger themed bald lady by Gregor Punchatz is a seperate entity).
Mechanically? The classic Arch-vile role wasn't really carried over, but Eternal's Arch-vile is like an upgrade from both the D3 Arch-vile and 2016's Summoner.

Cyberdemon:

Almost a tie between D3 and 2016:
D3 has a weird thing on its back with a tail, that also connects to its head; 2 cyber legs; arm cannon on the other side.
2016 Baalgar has a complex mouth, 4 eyes, an almost "rock-like" design due to its necrotic state, different looking horns, the glowy thing on his chest, a cyberleg covered by his "tree/rock-like" skin and the arm blade.
Mechanically, 2016 expands on the moveset and D3 Cybie's main gimmick is requiring the Soul Cube to be killed.
Meanwhile, Tyrant is a reindition of the classic design but with features and ideas from the 2016 Cybie (And still doesn't have hooves or backward knees) while its moveset is like a diet version of 2016 Cybie's moveset but has that homing floor flame thing.
Honorable mentions: The cut red D64 "double" cyberdemon and Wolf RPG's Harbinger of Doom, they're like 2 extreme opposites and 2 different sides of the Cyberdemon.

Spider Mastermind:

So far, we only got the 2016 SMM.
Its design is a more advanced, modern take on the classic concept and its moveset is a lot more complex, while the hitscan chaingun (Secretly an autoshotgun) is replaced by a plasma rifle.
Honorable mention: Maybe the D3 concept art, though 2016 had art of its SMM with a screen on her back showing off Olivia Pierce.
(Also, in D1 it originally was going to have a "magic" attack as seen in some unused sprite).
The Mother Demon may not really count but she's also a giant bug mom.

Icon of Sin:

Eternal's IOS is an obvious deviation from the Classic: A giant armored titan that attacks on his own, while the player is on top of 2 buildings.
As opposed to a demonic face attached to a wall shooting spawing cubes and letting demons attack the player (But even Final Doom and one of D2 Master Levels had some weird spins on the concept).
D2RPG has an interesting take because in a way, it's an extension to the typical D2 IOS but visually different.
But then D2RPG forces the player to fight the IOS 1v1, in form of the "VIRTUAL ICON OF SIN".
D2RPG IOS also talks to the player as his own character, which is different from the Eternal IOS being used by the Khan Maykr and fueled by the soul of the Betrayer's son.

Maybe this post was done better by someone, could also be worded better or researched better.

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Pub: 15 Oct 2022 18:57 UTC
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