Self-Constructed Being

Having a corporeal form is pretty nifty, you can do stuff like walk and talk. Sometimes however you run into a problem: you have no body worth noting. Perhaps you're a robot who's been reduced to a Heart Drive, a ghost who has to possess someone, or an alien who luckily can regenerate From a Single Cell.

This is the trope you need if you have to construct your own body before the nifty stuff you plan to do can be done. If you're a villain you can try to Take Over the World, if you're a hero you can try to save it, and if you are anybody else you get another chance to visit TV Tropes.

Unless the person bringing themselves back to life are also able to conjure up extra clothes to go with it, they very well might be Naked on Revival.

Anime and Manga

 * Ronin Warriors: Talpa had to (re)build his body during the series.
 * Cell from Dragonball Z.
 * Monster Rancher had the first two seasons where Moo is trying to dig his body out of the ice while, conversely, the Heroes search for the Phoenix.
 * In Inuyasha, an early Monster of the Week was a mask that wanted a body. The bad news: it caused its wearer to decay rapidly (as in, from human to crude oil in seconds.)
 * The Godhand from Berserk. Since they are not part of the physical plane and therefore have no physical bodies, they have to manifest through some material in order to make a presence in the physical world. But every 1000 years, they have the opportunity to reincarnate themselves into the physical world with a corporeal body.

Comics

 * In Watchmen after Dr. Osterman is disintegrated he spends some time slowly learning how to use his new powers to reconstruct a physical body to inhabit. It's not clear if he gains any benefit from having one, or if he just feels more comfortable being human-shaped.

Film

 * Hardware: a Wetware CPU skull has a bit more life than previously imagined.
 * Hellraiser: Frank Cotton built his body from a single drop of blood (and a few bystanders).
 * Virus: An alien energy being uses machine and human parts to construct bodies for itself.
 * Watchmen: In both the film and the original comic, Dr. Manhattan rebuilds his body from elementary particles following getting trapped in an Intrinsic Field Subtractor....

Literature

 * Journey to the West: The monkey king started as a rock.
 * Harry Potter: The Myth Arc of the first four Harry Potter books covers Voldemort's various attempts to take a physical form, and ultimately rebuild his own body, culminating in his confrontation with Harry in Goblet of Fire. Subsequent books cover his ascent to power.
 * In the Star Trek Expanded Universe book of fan-submitted short stories, Strange New Worlds V, [[spoiler: Commander Riker falls victim to a seed of
 * In the Percy Jackson and The Olympians series, the good guys are trying to stop Kronos from rebuilding his body (which was torn to pieces long ago) and returning to the world.
 * In Einsteins Bridge, The Hive have taken over several worlds by making tiny robots by light though tiny wormholes that builds into new Hive on that world.
 * In the in-universe dwarven myths of Discworld, their creator Tak wrote himself before he could write the world and the laws.

Live Action Television

 * The Master in the new Doctor Who "The End of Time".
 * In The Sarah Connor Chronicles, the heroes discovered that Skynet was sending Terminators back in time to ensure Skynet's creation.
 * In Kamen Rider ZO, Doras was initially seen as a small sphere who absorbed various metal objects around him in order to take on his monster form.
 * In Kamen Rider Double, the T-Rex Dopant is a head with legs until pulling in all manner of objects to form into a massive dinosaur.
 * Power Rangers SPD: The Man Behind the Man is a giant brain using the guys we thought are the main bad guys in order to build a Humongous Mecha body.
 * Power Rangers Lightspeed Rescue: Though gaining a new body wasn't her main goal, Queen Bansheera was still sealed away and when brought into this world, her body was incomplete because the ceremony was interrupted. She spent much of the series as a face in a barely mobile chunk of rock until she

Tabletop RPG

 * Call of Cthulhu (tabletop game) Dreamlands supplement, adventure "Pickman's Student". A proto Great Old One named Ghadamon spends the adventure slowly taking over the body of a human being so he can enter the waking world.
 * In Exalted, The Fair Folk --eldritch maelstroms of passions from outside reality-- must take an Assumption to enter Creation, lest they will be Calcified. Such form tend to be dramatic to the extreme: an indescribably beautiful lady, a towering man-beast monstrosity, or an artist whose performances moves hearts (and steals souls).

Video Games

 * Zelda II: The Adventure of Link: The baddies are planning to resurrect Ganon... using you as a sacrifice.

Web Comics

 * In Schlock Mercenary Petey is this to the evil Ob'enn. He went from a backup copy of the AI of a destroyed ship to being the nigh-omnipotent Fleetmind.
 * Xykon regrows his body as he rebuilds his army in Order of the Stick and prepares to prove himself a Not-So-Harmless Villain.
 * Kid Radd:

Western Animation

 * Swat Kats: the episode known as Unlikely Alloys has a tiny repair robot balloon up to Very Humongous Mecha size after assimilating a lot of technology, then it's creator.
 * Jackie Chan Adventures: Shendu had to (re)build his body during the series.
 * Ben 10: Vilgax spent most of the first season in a tank regenerating.
 * Megatron spends the first season of Transformers Animated as a head attempting to build a new body.
 * Teenage Mutant Ninja Turtles 1987: Krang is obsessed with getting his robot body working.
 * X-Men: Evolution,.