Spare Body Parts

Shepard: [The Normandy was] destroyed in a Collector surprise attack. I ended up spaced.
Wrex: Well, you look good. Ah, the benefits of a redundant nervous system.
Shepard: Yeah, humans don't have that.
Wrex: Oh, it must have been painful, then. [evil grin]

— Mass Effect 2

A Subtrope of either Bizarre Alien Biology or Body Horror, depending on how many of which parts the creature or person is "meant" to have. Humans have two eyes, two legs, two arms, two lungs, one mouth, etc., as do most of our most familiar animals. Want to make a race seem alien? Give them extra of something.

Subtropes include:

• Extra Digits
• Extra Eyes
• Multiboobage
• Multiple Head Case
• Multiple-Tailed Beast
• Too Many Mouths
• Triple Nipple
• Vertebrate with Extra Limbs
  • Multi-Armed and Dangerous
  • Our Centaurs Are Different
  • Spider Limbs
  • Winged Humanoid

Can overlap with Little Bit Beastly, if the character has both human and animal ears.

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Examples:

Comic Books

• Part 6 of the Marvel Fact Files says that the Kree have duplicates of several internal organs.

Films — Animation

• In Turning Red, when partially transformed, Mei keeps both her human ears alongside her panda ears.

Film — Live-Action

• In Coneheads, we learn that the Remulakians have at least four rows of teeth.

Literature

• In The Mote in God's Eye and its sequels, Moties have one large, powerful hand on their left side, and two smaller, more dexterous hands on their right side.
• The Hitchhiker's Guide to the Galaxy's Zaphod Beeblebrox: Two heads, three arms. The extras aren't standard for his race, he had them added.
• The Tyrathca of The Night's Dawn Trilogy. Females of the breeder caste have multiple sets of ovaries, each becoming fertile at a different time in her cycle, and each producing a different kind of egg that hatches into a different caste. (The Tyrathca are a Eusocial species with multiple castes that evolved to perform specialized tasks such as Hunter, Soldier, Farmer, etc. Only the Breeders are fertile and fully intelligent. All other castes are little more then beasts of burden lacking the intelligence to do anything but the task they evolved for.)
• S.L. Viehl uses this a lot in the Stardoc series. For example, there's an alien in the first book with two separate digestive tracts.
• In Animorphs, Andalites sort of resemble centaurs, which obviously means extra legs, but even their humanoid parts have seven fingers on each hand, two extra eyes on stalks, and apparently three hearts.
• Discworld: It's offhandedly mentioned that banshees have two hearts in Going Postal. This can also apply to Igors - they're not born with the extras, they're just very good at Self-Surgery.
  Vimes: We know your heart is in the right place —
  Igor: They are in the right places, sir.

Live-Action TV

• Babylon 5: Centauri have two hearts. Unlike Klingons, Centauri can die if either heart fails. In the season five episode "The Very Long Night of Londo Mollari", in which Londo suffers a heart attack, we find out more details: the right heart is a large and simple muscle, much like a human heart, whereas the left heart is a knot of blood vessels that gives the blood pressure an extra kick and also functions much as a human kidney (mollusks on earth have a somewhat similar system). Surgery on the left heart is correspondingly difficult due to its complexity. The left heart is considered the seat of the soul in traditional Centauri culture. Males also have six prehensile penises sprouting from their backs (aligned in pairs along the spine), corresponding to six similarly-arranged slits in the female.
• The lounge singers in Battlestar Galactica (1978) have two mouths each. Meanwhile, those insectoid things have four arms. Eek, in both cases.
• Doctor Who:
  • Time Lords have two hearts. The Doctor is no exception. Some of the spinoff novels have added a great deal of lore regarding Time Lord hearts, including:
    • Time Lords have only one heart in their first incarnation and the second one develops, along with other physiological advantages like the respiratory bypass system, as a result of their first regeneration.^note This bit of lore was devised primarily to clear up the continuity issue of the First Doctor having only one heart, with the two-hearted Doctor not being established until the Third Doctor's debut story. (Although some other novels say otherwise.)
    • The hearts are categorised as a "primary" and a "secondary". Quite what this means in a physiological sense (e.g., is one heart more powerful than the other, do they have somewhat different functions) is never made quite clear.
    • The Eighth Doctor novel The Adventuress of Henrietta Street suggests that the second heart might be the source of some sort of psychic link between the Time Lords and Gallifrey, and the control centre for their various alien traits (regeneration, rapid healing, sensitivity to time etc).
    • Both the spinoff novels and the new series indicate that the Doctor is capable of living with only one functioning heart, though it's very painful and can't be kept up for long.
    • "The Woman Who Fell to Earth" reveals that the two hearts result in two separate pulses.
  • "Extremis", meanwhile, reveals Time Lords also have three brainstems.
  • "The Girl Who Waited": The Apalapucians are another Human Alien species with two hearts.
  • Iris Wildthyme and the Panda Invasion shows that Iris has two livers as a nod to The Doctor having two hearts.
  • In Doctor Who Meets Scratchman, Charon mentions having to take a Martian Warlord to Hell after taking a sickle to his third spleen.
• Star Trek's Klingons have a number of physiological redundancies such as an extra liver, eight-chambered heart, a double set of ribs, redundant nerve systems and an extra lung. In at least one episode where that's brought up, the show also points out that this has its disadvantages; while it allows for survival if one of them fails, the fact that there are more of them increases the chance of one going wrong in the first place, causing problems in the process. It's not just internal organs; Star Trek: Discovery once shows a Klingon taking a leak, and there are two streams.
• The warrior race, Luxans from Farscape have two hearts.

Religion

• The Hindu deities Kali and Vishnu have two pairs of arms (and the former can upgrade to five), and Surya is sometimes depicted with four arms.
• A specific Buddha exists who literally has a thousand eyes (all the better to see with) and an equal number of arms (the ultimate multi-tasker).
• The biblical Book of Revelation contains many beasts with extra heads, eyes, horns, and so on, including a beast with seven heads and four heavenly creatures that are completely covered in eyes.
• The Hekatonkheires of Greek myth, which werepersonifications of natural disasters, each had one hundred heads and arms.

Tabletop Games

• Gamma World. The mutant race known as the orlen were humanoids with two heads and four arms. Additionally, players could create mutant characters with any number of extra parts.
• In Warhammer 40,000, the Genestealer Hybrids, an Alienesque cult designed by the equally Alienesque Tyranids, have six limbs, four of which are the normal mammal-human ones, and the two (or sometimes only one) others are clawed and chitin-ed.
  • For that matter, the Space Marines have 19 extra organs implanted although only two of them are actually spares for existing organs (an extra heart and lung).

Video Games

• Gilgamesh from the Final Fantasy series had at least eight arms.
• In Mass Effect, the batarians have four eyes. When humans, or other two-eyed races have conversations with them they get confused because they don't know what to focus on, leading to the batarian attitude that humans are stupid.
  • Then there's the memorable quote about krogan testicle transplants: "Some go for as much as 10,000 credits a piece, that's 40,000 for the full set." Humans say someone's got a pair - krogan have a quad.
  • The krogan take this trope to its Logical Extreme, having evolved redundant internal organs as a result of living on a Death World. At one point EDI mentions a krogan's tertiary organ systems, meaning even their spares have spares. And when one of the redundant ones kick in, it triggers an intense adrenaline surge that permits them to knock people aside like ragdolls. Never attack a krogan with anything less than what you'd use to demolish a building. You'll just make him mad.
  • See the page quote for how Wrex reacts to discovering that humans don't have a redundant nervous system to survive being spaced.
• The Shokan (the race of Goro and Sheeva) in Mortal Kombat all have four arms.

Web Animation

• Some Faunus in RWBY have animal ears in addition to their human ones. Sun, a monkey Faunus, has a fully prehensile tail.

Webcomics

• Dwarves in The Order of the Stick have two livers. This is the in-story justification for their +2 fortitude save against poison, and why it is so hard for them to die from alcohol poisoning. Actually managing to die of alcohol poisoning counts as a death in battle for religious reasons, in respect for the valiant stand against the inevitable the livers made.
• Serix: The specs for Rees's clone bodies list her as having four lungs, four hearts, and three stomachs. The Made of Iron Sheriff Ludo also boasts about having thirty-seven hearts after getting a hole blown through his torso.

Western Animation

• Futurama:
  • In one episode, Bender is in an accident that costs him the use of his arms. Beck gives him tiny replacement arms mounted on his neck (which Beck uses to play the harmonica). Later, when Bender regains the use of his original arms, he uses both pairs in expressions.
  • Zoidberg as well. He's got several of everything, and can even talk through a vivisection (much to the dismay of the vivisectors).
    Surgeon: Heart.
    Zoidberg: Take! I've got four of them.
• In Gravity Falls, Mermando, a merman, casually mentions that he has "like, seventeen hearts. Horrifying but true!"
• In the Invader Zim episode "Dark Harvest" when there's a physical coming up and Zim realises the nurse would figure out he's not human after examining him, he goes around stealing organs from the other students. Of course, with Zim being Zim he goes over the top and steals more organs than he really needs. Lucky for him the nurse is an idiot and doesn't see anything amiss.
• Men in Black: The Series features the Sintillians. Not only do they have two hearts, but neither heart ever stops working; so long as they have at least one and "nobody drops a piano on them", they're effectively immortal. When Alpha steals a Sintillian's heart, K makes it clear to J that the Organ Theft is still a big deal. "You have ten toes. You wake up one morning with one missing, how would you feel?"
• Teen Titans (2003): Starfire is quite happy she has nine stomachs when she is spoonfed some Mind Controlling pie and spits it back before digesting it.

Real Life

• The real-life equivalent of this trope is called "supernumerary body part".
• Most people have two kidneys and can survive with one. Which is fortunate, as it's one of the most failure-prone organs due to its complexity, so you have a spare if one of yours fails or both of a relative's kidneys fail. That said, it's not unknown for people to be born with a single large kidney or three or four small ones too.
• Pretty much everyone has individual variations and redundancies within their body's network of blood vessels, particularly in its veins and smaller arteries. That's why an angiogram or other vessel-mapping procedure is usually carried out before surgery, to ensure there won't be any mid-operation surprises (e.g. discovering the kidney being donated has more than one renal artery).
• Four parathyroid glands is the norm for humans, but some people have six, eight, or even more.

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