In the world of fiction, life and death aren't always black and white, there's a very large and very varied grey area - see Only Mostly Dead. One aspect of which is characters that aren't dead so much as corporally challenged.
The Disembodied was once human but lost his body through a bizarre accident without actually dying. In other words, they're the Technically Living Zombie variant of a ghost. This may happen through Astral Projection and then having your body destroyed, or being unable to go back for one reason or another.
- Fullmetal Alchemist: Alphonse Elric lost his body due to a botched attempt at human transmutation and ended up as a soul stuck inside a suit of armour. It's eventually discovered his body is still whole within the Gate of Truth, and without that Al couldn't even be alive in his current state.
- In Darker Than Black, a "Contractor" is a Differently Powered Individual who has to perform a Renumeration for every use of their power. The only exception are Contractors who have "fully paid off their contract." One of the only ways this is shown is when a character who has the ability to take over someone else's body has their original body destroyed while they're in someone else's.
- Variable Geo centers around The Jahana Group's attempt to resurrect their deceased leader, Miranda Jahana, by finding a suitably powerful body for her spirit to inhabit. Which is why they manipulate Satomi into entering the VG Tournament.
- Hellboy: Johann Kraus was a German psychic whose body was destroyed due to a psychic disaster. His ectoplasmic form 'survived', but needs to be constantly contained to prevent it from dispersing.
- The Legion of Super-Heroes' Wildfire, sort of like Johann Kraus, is a being of pure energy who needs to wear a suit to survive.
- A minor student at the Xavier academy in the X-Men comics, Dummy, was also basically a suit with sentient gas inside of it.
- A variation appears in ElfQuest. Unfortunately, it needs a lot of spoilers because it happens late in the story. Winnowill chooses to die in order that her disembodied malevolent soul can destroy her enemies and wreak havoc. Instead, Rayek absorbs her soul and holds her captive in his own body. It's an endless, bitter struggle and we haven't seen the end of it yet.
- Holocaust from Marvel Comics' Age of Apocalypse and Exiles.
- Dr. Manhattan from Watchmen was completely torn apart at an atomic level due to a Freak Lab Accident, but his consciousness remained and very gradually was able to piece together a body. He doesn't NEED the body, though. If his body is destroyed again, his mind will be unaffected, and can easily make a new body this time.
- Voldemort in Harry Potter, following a backfired curse. He can't die as long as at least one of his Horcruxes exists, but actually reincarnating himself takes quite a bit of effort and an entire book's worth of convoluted scheming.
- In the German pulp sci-fi magazine series Perry Rhodan, a man named Ernst Ellert was among the first generation of known "mutants" (people with psychic powers) and was a member of the first Mutant Corps; his power was the ability to separate his mind (or astral body, or soul, whatever you want to call it) from his physical body and travel through time and space along temporal strands. He could travel to the past, or could select the statistically most probable future among several potential futures and follow the strand to see where it led. He died a heroic death in 1972 in an accident with high voltage, but the shock of dying completely separated his astral body from his body and he was hurled through time and space. After a long odyssey (during which he learned that his astral body could enter and control the bodies of physical beings), he eventually managed to return to 21st century Earth. For a short time, he was even forced to "possess" his own preserved dead body, until the deteriorating state of the body put it beyond his powers. In the year 4013, Ellert was given a new material body, created by advanced alien technology out of billions of sentient nanomachines. The new body was humanoid, although Ellert's control over the nanites allowed him to transform his body into a cloud of nanomachines and solidify it again at will, i.e. if he wanted to walk through walls.
- General Zod in Smallville until the events of "Dominion".
- Earlier in the series, the episode "Spirit" had Dawn Stiles, who crashed her car into an area full of Kryptonite. Dawn blurs the line between this trope and An Astral Projection, Not a Ghost since while her spirit is around possessing people, her body is alive until she possesses a nurse and kills her own body.
- Doctor Who has Omega in "The Three Doctors" (he's been so eaten away by anti-matter that only his will exists) and, most recently, Dr. Simeon, aka The Great Intelligence.
- The Outer Limits (1995): In the episode "Free Spirit", a human test subject became a disembodied body-possessing spirit after his body was terminated in the middle of a mind transference experiment. Then he comes back for revenge against the scientists responsible for his death.
- Stargate Atlantis: A group of rogue Asurans (killer androids made of nanites related to the Replicators in SG-1) attempt to achieve ascension by destroying their original bodies and becoming incorporeal, but because they aren't organic this simply left them in a transient state.
- Allen the Amorphous Cloud of Gas in Dilbert was so uncommitted that eventually the particles that make him up became bored and stopped binding. Now he exists only as a faint odour near the copy room.
- In City of Heroes, Positron was a guy who was essentially converted completely into antimatter. He was stuck permanently inside his armor, and when it was damaged, he actually started leaking out. At one point, Badass Normal Manticore successfully scares off a whole group of powerful supervillains by threatening to put an arrow through Positron, turning the guy into an antimatter bomb. One of the comic storylines ended with Positron having a wish for a regular human body granted, with his character in-game changed to reflect this.
- In BlazBlue, Yuuki Terumi is the disembodied spirit of the Susanoo Unit itself. He hated serving his "sister" Amaterasu and sought to usurp her, but his own body's hardwired limitations prevented him from doing so directly, so he had to abandon it to set his plans in motion. He eventually returns to his original body in the last installment of the series Central Fiction and serves as the franchise's Final Boss.
- Honkai Impact 3rd: In the backstory, Seele Vollerei was put in an experiment related to quantum physics. Unfortunately for her, it Went Horribly Wrong, causing her body to dissipate into atoms. However, her consciousness survived in the "Imaginary Space", and she becomes unable to interact with any kind of matter, nor could she be heard or interacted with. Bronya (her friend), knowing that she's still alive, vowed to find a way to restore her. In chapter 11 of the game, they finally meet each other again when Bronya stumbled into the Sea of Quanta. Then, after a series of struggles, the two manage to go back to the real world, and Seele regains her physical form.
- Issue #10 of The Secret World reveals that the Black Signal, initially introduced as an incorporeal Eldritch Abomination with a penchant for calling itself John, is actually one of these: once a human member of the Fear Nothing Foundation, he supposedly ended his life detonating a Filth-bomb on the Tokyo subway... but instead of being killed or merely infected, the pure Filth at the epicenter of the blast converted him into a disembodied Filth-entity capable of possessing any mind touched by the Filth - or tech, which he greatly prefers.
- The ghosts in Pac-Man and the Ghostly Adventures are technically not completely dead in the sense, as they were stripped of their corporal bodies as punishment for trying to take over Pac-World.