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Machine Blood

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"If you prick me, do I not... leak?"
Data, Star Trek: The Next Generation, "The Naked Now"

In works centered around or containing robots, vehicles, Mechanical Lifeforms androids, machines, mecha, etc., creators add a human element to the artificially created beings to set the tone and so that the audience will have an easier time relating to the characters. Using oil, coolant, battery acid, hydraulic fluid or some type of unusually colored liquid as a stand-in for blood makes things look a lot more serious and visceral in action scenes. It also makes the audience more sympathetic if the "bleeding" robot is one of the protagonists or a tragic character.

In some works, the fluid is red and visually-indistinguishable from actual blood. In others, it really is artificial blood and the mechanical life forms are Ridiculously Human Robots.

This may be an android's Robotic Reveal, confirming it's not biologically human. In other cases it may not reveal anything - if it's not confirmed whether the Ambiguous Robots are bleeding or leaking, it only makes them more ambiguous.


Sometimes used as a way to pass the censors in G and PG-rated works where real blood, especially excessive blood, is considered inappropriate for younger audiences. If the fluid looks too much like blood in a work that was originally from a foreign country, some regional localizations are likely to either change it to look like regular oil or just edit out the blood completely. What Measure Is a Non-Human? is at play as people are generally more comfortable with robots/machine character "bleeding" than human characters as long as their blood doesn't look human.

See also Alien Blood, where aliens have weirdly colored blood and Symbolic Blood, where something else is used in place of blood either for comedy or for symbolism.



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    Anime & Manga 
  • Most of the Boomers in Bubblegum Crisis tended to bleed bright orange fluid when damaged, which is unusual for robotic enemies.
  • In Dragon Ball Z, Android 19, Android 20/Dr. Gero, and Android 16 leaked red oil when damaged. Vegeta even notices this with 19. It comes so close to looking like actual blood that some of it was removed in the edited version. Mecha Frieza also has magenta colored oil in his machine parts, seen when he clinches his now robotic hand and magenta oil leaks from it.
  • In Ghost in the Shell whenever an android gets severely damaged, white artificial blood splatters all over the place.
  • Gundam:
    • In The 08th MS Team, the battle between Norris and the Team has this when Norris stabs a guntank, resulting in a massive gout of oil being sprayed across his mobile suit.
    • Riddhe's Delta Plus bleeds the same way in Mobile Suit Gundam Unicorn, when the Banshee destroys it.
  • Negima! Magister Negi Magi has this when the fourth form of Fate, Quartum appears to promptly slash Chachamaru in half at the mid-section, leaving her bleeding and crying fluids all over the deck of the Great Paru-sama, implying that she's powered by hydraulics.
  • In Neon Genesis Evangelion, the titular Humongous Mecha fight hand-to-hand with monsters strong enough to pierce their armor or even sever their limbs. When this happens, the Evangelions bleed - a lot. All of them bleed red, except for Unit 02, which bleeds purplish-blue. This is because an Evangelion is not a robot, but a genetically-engineered Cyborg Eldritch Abomination encased in Powered Armor.
    • When they are not in operation, the Evangelions are stored not in a conventional hangar or drydock, but in a giant tank of water. This peaceful bath doesn't suggest violence the way blood does - instead it is reminiscent of amniotic fluid in a womb. It adds to the Evas' appearance as Ambiguous Robots.
  • Shippu! Iron Leaguer: When injured, the Iron Leaguers bleed oil. Nonetheless, it looks painful enough to make the viewers cringe.
  • Brave Police J-Decker: There's an episode where Deckerd goes off on his own to find the criminals and is shot multiple times, leaking blood-like fluids from all his holes even from his mouth and unable to get up and walk. He's fine almost immediately after his friends show up to save him.
  • D.Gray-Man: The human-based machines known as akumas have red "blood-oil" (that looks exactly like regular blood).

    Comic Books 
  • Invoked in one issue of The Transformers when Blaster discovers a puddle of leaked Transformer fuel and, after verifying that's what it is, calls it "the lifeblood of my people".
  • In The Transformers (IDW), they get a lot of mileage out of having Cybertronians bleed energon when wounded, donate vials of "innermost energon" to sick loved ones and so on. Since energon is a magenta-pink shade, this also means that Arcee's pink colouring is supposed to paint her as a bloodthirsty maniac.
  • The people of the Robot Kingdom of Saga have literal Blue Blood.

    Fan Works 
  • Dungeon Keeper Ami: Ami's ice golems are humanoid, and, when damaged, "bleed" water, which, when covered in a glamour a.k.a illusion, to appear human, actually becomes the blood.
  • Mega Man: Defender of the Human Race sometimes uses oil as an analogy for blood. One of the biggest instances is at the end of Episode 11 after Mega Man's severe damage from the Mad Grinder, with Dr. Light hooking up an oil feed tube in a manner akin to a blood transfusion and Proto Man looking at how his own hands and chest were stained as he carried Mega Man to safety.

    Films — Animation 
  • When the Lemons blow up Rod "Torque" Redline in Cars 2, we actually see a puddle of oil trickle under the Lemons' tires once Redline is finally dead.
  • The Brave Little Toaster: After Elmo St. Peters takes out the motor in his (anthromorphic) blender, electrical fluid is seen dripping from the table to the floor.

    Films — Live-Action 
  • The androids in the Alien films "bleed" a milky fluid when injured. Since these are also Ridiculously Human Robots, it works as a Robotic Reveal in the first film, when one character bleeds white from a cut and spews it everywhere as they take damage and gets their head torn off.
  • I, Robot: When Sonny is shot in his introduction, he begins leaking some kind of liquid metal from the damaged hoses. Apparently, in 2035, they're using Osmium in their hydraulics.
  • During the final battle of Iron Man 2, the Hammer drones spurt oil when Iron Man and War Machine blow them apart. The fight scene was choreographed by Genndy Tartakovsky, who had used a similar style in Samurai Jack (see below under Western Animation).
  • In Short Circuit 2, Johnny 5 is leaking battery fluid after being damaged by the villains. His friend Ben outright says he's bleeding to death, and he even applies a makeshift tourniquet.
  • In the Transformers movies, blood from the bots is represented in some cases by fluorescent blue liquid (which the fandom believes is Energon).
    • In Dark of the Moon, Autobots and Decepticons both bleed copious amounts of vibrantly colored fluids when shot and hacked apart, averting the previous films' use of Bloodless Carnage.
  • In the sci-fi film Time Under Fire, the androids bleed mercury.
  • Wild Wild West. While Dr. Loveless is riding his spider robot inside his giant Spider Tank, Artemus Gordon shoots the robot in one of its legs. A spray of liquid (presumably hydraulic fluid) sprays out of it like High-Pressure Blood, and the robot slowly collapses to the deck.
  • Virtuosity: Sid 6.7, the villain, is given a body woven from nanites; when shot or stabbed he sprays the nanites as a blue fluid (and since he can regenerate from any injury, this happens a LOT).
  • The androids in Halloween III: Season of the Witch have yellow oil inside of them.
  • Edward Scissorhands: Edward has artificial blood.


    Live-Action TV 
  • In Altered Carbon synths have blue "blood", it's notable when a supposed synth of Quelcrist Falconer bleeds red.
  • Kamen Rider Zero-One: Damaged HumaGear bleed blue fluid of unknown purpose. Magia, the hacked HumaGear, don't bleed anything.
  • Doctor Who: In "Tomb of the Cybermen," something that looks like shaving cream erupts from a dying Cyberman's chest-box.
  • In Robot Combat League, the robot fighters sometimes get so damaged, they spray hydraulic fluid everywhere. Without hydraulic fluid, the robots' limbs won't work properly, essentially paralyzing the limbs and leaving the robot at a disadvantage.
  • In Star Trek: The Next Generation, Data and Lore the androids have a liquid in them to lubricate their mechanics, so if one was to "injure" one of them in the right place, this liquid will leak out, which has been likened to bleeding. In addition, if one was to put their hand on Data or Lore's wrist, they would feel the lubricant oozing through in a manner similar.
  • Stargate SG-1: In "Tin Man", SG-1 first realize they've been turned into robots when Dr. Fraiser goes to draw blood from Jack and instead gets something that looks like white lithium grease.

    Tabletop Games 
  • Ars Magica: A Hermetic automaton's "blood" is its impetus, an animated fluid that drives its body and fuels some of its special powers. This can be anything from various alchemical solutions to purified mercury to liquid fire, with more refined materials allowing for a more powerful automaton.
  • Pathfinder and Starfinder: Androids, artificial humanoids who very closely resemble humans but are made out of synthetic materials, utilize a colorless mixture of coolant fluids and nanomachines as "blood". Due to this, they're as vulnerable as humanoids are to bleed effects, unlike pure Constructs.

    Video Games 
  • Alien: Isolation: Working Joes "bleed" a milky fluid when injured like the androids from the movies. However, they were created by Seegson to serve as a cheaper alternative to Weyland-Yutani's androids.
  • Banjo-Tooie: Mingy Jongo has a green fluid, possibly either motor oil or coolant, spewing out of his neck when his head falls off after he is defeated by Banjo and Kazooie.
  • BlazBlue: Tager, a huge cyborg, has his blood type listed as "natural oil".
  • Detroit: Become Human: Thirium, colloquially, the "blue blood" of androids, that they need to function.
  • Mega Man
  • The robot/cyborg characters from Mortal Kombat would have their "blood" coloured black or blue as if it were oil being knocked out from the uppercut.
  • In Metal Gear Solid 4: Guns of the Patriots, Raiden bleeds white artificial blood following his transformation into a Cyborg Ninja by the Patriots. This leads to a lot of very suggestive imagery when Vamp drinks some of his blood.
  • In Metal Gear Rising: Revengeance red blood and white "blood" are used to distinguish cyborgs/droids and unmodified humans. Jetstream Sam's boss fight ends with an Unrobotic Reveal, where the fact they bleed red is used to show that they have very few cyborg parts. At least in regions where the red blood isn't censored.
  • In Metal Gear Solid 2, the Metal Gear Rays which Raiden fights near the end bleed a white fluid, which serves a similar role to blood in their self-repair systems.
  • In Xenoblade Chronicles X, as part of the Robotic Reveal, the Player Character bleeds blue circulatory plasma when they get their arm blasted off.
  • Alien-made Machine Lifeforms in NieR: Automata "bleed" oil when you damage them, as do the human-constructed androids. This is an early hint that they are built upon the same technology.
  • Nanobreaker had various robot/cyborg enemies, and a menu where you could decide what of wide range of colors of "blood" they would bleed as you viciously dispatch them with your shapeshifting sword. For great humor, select the "random" option, and turn your battlefield into a particularly colorful impressionistic painting!
  • Used for censorship in Team Fortress 2's Meet The Soldier animated short. In the original, there is a lot of blood and gore, but in the German version, the blood is replaced with oil, the bones are replaced with springs, and the gore is replaced with miscellaneous items like rubber ducks, cogs, etc., implying that all the mercenaries are robots.
  • Bolt in Paladins bleeds oil when shot at.
  • In People Playground, androids bleed brown oil while humans bleed red blood.
  • The Geth in Mass Effect bleed a white fluid when shot.
  • Oil platters on the player’s helmet when melee killing a battle droid in Star Wars: Republic Commando. Fortunately, clone commandos have the Star Wars equivalent to windshield wipers built in.

    Visual Novels 

    Web Comics 
  • Strange School: The robotic Students 'bleed' black machine oil when injured.

    Western Animation 
  • Beast Wars: Whenever some bot gets hit, bits of metal and hydraulic fluid go everywhere. This is apparently called "mech fluid", and while Cheetor claims it's not real blood, given their organic alternate mode it may serve a similar purpose. Similar enough for Tarantulas to want to drink Cheetor's, anyway...
    "I don’t have any real blood, just mech fluid."
    "Oh, my filters will adjust. It is the act I enjoy more than the nourishment."
  • Dino Trux: The only two instances of a Dinotrux suffering an injury that causes them to "bleed" are "Sawmetradon" where the titular Splitter cuts open one of Ty's oil lines with his saws and "Downshift", where Dozer blows a gasket fighting D-Structs and leaks coolant. The former is treated more like blood as Revvit immediately calls for a retreat to repair the wound stressing that Ty could suffer engine failure if allowed to bleed out.
  • In Futurama episode "The Silence of the Clamps", a farmbot who looks like Bender is mistakenly shot to death by Bender's Psycho Ex-Girlfriend. Instead of blood, the dying robot is bleeding oil from his mouth.
    • In "The Honking", after Bender goes out all night as a Werecar, he wakes the next morning laying in a puddle with what looks like dark red blood that's splattered on his mouth. Bender identifies it as transmission fluid.
  • Robots in Samurai Jack spray oil and electricity as if they were High-Pressure Blood. Word of God says this was done so they could include violent, high-octane action sequences in the style of old-school samurai movies but still be age-appropriate for a TV-PG show. They also used aliens and monsters who "bleed" slime or goo.
  • In Transformers: Prime all the 'bots "bleed" Energon. A lot. Sometimes they're even shown lying in a pool of it while near death.

Alternative Title(s): Robot Blood


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