Although meant to be a Milestone Celebration of the Doom franchise, Doom Eternal contains multiple references to works by different creators and companies other than id Software and Bethesda. For shout outs to other works by Id and Bethesda, see the Mythology Gag page.
- The E3 2018 teaser of the Doom Slayer crushing a demon's skull with his foot references Terminator 2: Judgment Day, in the prologue portion where a T-800 stomps on a human skull.
- The Doom Slayer's Praetor Suit for Eternal sports a retractable "Doomblade" and an "Equipment Launcher", mounted to the suit's left gauntlet and shoulder, respectively, much like the eponymous Predator and its character design. Doubles as a Call-Back to Doom (2016) where one of the Slayer Testaments refers to him as the "Unchained Predator".
- As if to drive the point home, one of the Slayer's Glory Kills against a Prowler is grabbing it by the base of its neck and ripping out its spine
◊, similar to how the Predator takes skulls from humans as a trophy. - Another reference to the film occurs during the Super Gore Nest mission, during the final phase when the Doom Slayer has to escape to the extraction point, the mission objective text reads "Get to the Choppa".
- As if to drive the point home, one of the Slayer's Glory Kills against a Prowler is grabbing it by the base of its neck and ripping out its spine
- The Slayer's Plasma Rifle having the ability to overload enemy shields might be a reference to Dune, where the Holtzmann effect causes contact between shields and lasers to have a very explosive result.
- Game Director Marty Stratton and Creative Director Hugo Martin noted the scene of RoboCop walking through the Detroit police station for the first time and the T-800 "requisitioning equipment" as direct influences on the scene of the Doom Slayer walking through the Union Aerospace Corporation's command centre on Phobos while everyone stares in bewilderment.
- The shelves in the Slayer's office on the Fortress of Doom contain items referencing various pieces of media, including books, movies and, of course, video games (especially First Person Shooters) by other companies. (Jan 2020 demo event footage)
- U-NAT-CO Training Manual: Bomb Disposal.
- Mesa Science Monthly: Predicting Unforeseen Consequences.
- Von Braun: Onboard A.I. System Technical Manual.
- Liandri: A Brief History of Interplanetary Industry.
- Devilish Daggers & Other Assorted Pointy Objects.
- Why I'm So Great Pt II, By Dork Norkem.
- My Buddy Superfly, By Hiro Miyamoto.
- How to Win Friends and Kill Demons.
- Atlas Ripped and Teared.
- The Picture of Dorian Slay.
- The Caco in the Rye.
- Green Eggs and Pentagrams.
- 1984 Dead Demons.
- To Kill a Mockingdemon.
- The Great Gutsby.
- Demon Farm.
- The Very Hungry Cacodemon.
- The Power of Positive Ripping and Tearing.
- The Art of Rip and Tear.
- The Slayer's Tale.
- How to Stop Worrying and Start Slaying.
- The Man in the High Argent Tower.
- The Guts of Wrath.
- The Ripping Tree.
- Slayerhouse Five.
- Don Slayote.
- Slayenstein.
- Fifty Shades of Slay.
- Eat. Rip. Tear.
- The Count of Kadingir Cristo.
- Dungeons and Demons: 6th Edition
- There is a smorgasbord of shout-outs to be found in the Milestones.
- The Milestone for acquiring all Runes in a single save slot is "High Rune," complete with a thumbnail of the Doomguy dressed as McCree.
- One to Santa Claus Is Comin' to Town, of all things; the milestone for freezing 50 enemies with the Ice Bomb is "Warlock Of Winter."
- The icon for the "Turbo Boost" milestone is the Doom Slayer Naruto-running.
- The icon of Argentas Paladi shows the Doom Slayer in front of a Looney Tunes iris; which, as this is the absolute last unlockable in the game, all but directly states the famous phrase That's All, Folks!.
- The milestone for spending 50 seconds in the air as a Revenant in Battle Mode is "Float like a Butterfly".
- The icon for the "Lighter Than Air" milestone features Doomguy gliding through the sky on a pair of wings that are identical to Buzz Lightyear's.
- The name and icon for the "Dodge This" milestone are references to the famous rooftop duel from The Matrix.
- The milestone for completing the UAC Cultist Base is "I'm the Cult Leader now."
- The milestone for reaching Nekravol is "Hell Hath No Fury," a reference to The Mourning Bride by William Congreve.
- Creative Director Hugo Martin has noted that The Fortress of Doom, from its name to its looks to its various ancient relics and weapons, was directly inspired by Castle Grayskull from the Saturday morning cartoon He-Man and the Masters of the Universe (1983).
- Notably, when the Slayer reforges the Crucible Blade, he holds it aloft in a manner recalling He-Man's iconic "I have the power" pose.
- One of the advertisements you can find in the cityscapes is for "Mario's A la Carte Restaurant", saying that customers can "Stay on track with our Mystery Box Dinner."
- A few shoutouts can be found in the unlockable cosmetic skins:
- The Sentinel Training Armor's helmet strongly resembles the one worn by Goblin Slayer.
- The "Battle Mech" Ballista skin and profile icon share the exact same colour scheme with Evangelion Unit-01.
- One of the Hell Priests' crowns looks exactly like the stress symbol from Darkest Dungeon.
- As in DOOM (2016), dying in a pool of lava will cause the Slayer to give a thumbs up on the way down, as a send-up to Terminator 2: Judgment Day.
- In the first level, you can find a poster for a lost dog stating that it was "last seen with a branded swordsman" and goes by the name of "Gryffin", a clear reference to the two main characters of Berserk.
- Mars Core ends with the Doom Slayer making his way to an ancient underground city in Mars, similar to the plot of Total Recall (1990).
- If the wrecked mini-mechas and giant robots strewed across the destroyed landscape seem very familiar to Pacific Rim fans, that's because Hugo Martin worked on that movie's Jaeger designs. They're not as effective against demons as they are against kaiju, sadly.
- The "Party Mode" cheat code causes demons to burst apart into confetti if gibbed or headshot; similar to the Grunt Birthday Party Skull from Halo.
- Among the items sold by a convenience store in "ARC Complex" are packets of Lil'Bits.
- One of the Super Gore Nest challenges is called "War Pinkies", a likely reference to Black Sabbath's "War Pigs".
- You can spot drones◊ on the Doom Hunter Base level; they bear a strong resemblance to Imperial Probe Droids from Star Wars.
- The album cover for "BFG Division"◊ is very similar to the cover for Screaming for Vengeance◊, an album by Judas Priest.
- The design of Kalibas the Sightless Judge seems to be rather similar to that of Mother Brain from Metroid.
- An easter egg in Ancient Gods Part One briefly flashes a deliberately misspelled "DOOG Eternal", a rather obscure reference to hololive's Korone Inugami. The way it's activated (pressing the chainsaw button on the Runes menu) is also a reference to her comical overreaction to using the chainsaw in her Doom 64 and Doom (2016) playthroughs. Before its unceremonious removal within a day or two after its discoverynote , Microsoft's social media team confirmed that the easter egg was indeed about her, mentioning "yubis" in various social media posts.
- Looking into a specific grate within the sewers of the Master Level Super Gore Nest allows you to find the ever-innocuous Bar of Soap from DUSK.
- Near the start of the ARC Complex level, close to where the Mancubus collectible is found, there is a drawing◊ of a cat on a bloodied pillar, a reference to Stop Motion animator Lee Hardcastle and his Claycat's DOOM videos.
- As the Doom Slayer begins lighting the Torch of Kings in The Ancient Gods - Part Two, the shot of surviving Night Sentinels across Argent D'Nur seeing it lit is not so different than the warning beacons of Gondor stretching to Rohan.
- The "Barbarian" skin in the same DLC features a tanned Slayer with long hair wearing little besides a pair of leather briefs, making him resemble Arnold Schwarzenegger from Conan the Barbarian (1982).
- The Slayer's response to Davoth's last words is rather reminiscent of a certain soldier's riposte to a godlike AI.
- In the tutorial for the Sentinel Hammer, you have to do certain tasks before being able to use the hammer. Once you can use the hammer the game simply states "Stop! Hammertime!"
- Deag Ranak's scepter bears a strong resemblance to the one used by The Three-Eyed One.
- In the ARC Complex, there's a computer with a sticky note on it saying "not a mimic". Uh, we're fighting demons here, not Typhons.
