Necrozma is a Pokémon whose body appears to be constructed out of black crystalline material; its disproportionately large arms have three claws jutting out of them, as well as a single large whitish crystal protruding backwards from each arm. Its small legs bend backwards like a bird's and have three toes each. However, it does not seem to use them as it can naturally levitate through unknown methods. A single wing grows out of each of its shoulders, which resembles a hook. The large protrusion attached to its head is its tail, which is white in the back with a dark gray symbol resembling a star in the center. This part of the tail absorbs light that it converts to lasers, and glows when it does. The sides of its head and the top of its tail are covered in spikes. Its face is actually a prism-like object known as the brain prism, which possesses a collection of multicolored shapes that resemble eyes.
Dusk Mane Necrozma has the appearance of a Radiant Sun phase Solgaleo combined with parts of base Necrozma. Necrozma's tail splits into two and attaches to the sides of Solgaleo's torso. The front feet have five black claws attached to it with two V-shaped crystals on top of it while the back foot has only three claws. Necrozma's head and arm have attached onto Solgaleo's back as extra arms with the large crystals on Necrozma's arms disappearing in the process. The tail gains a three black spikes attached to each other. Solgaleo's face gains three spikes under the chin while a scalene triangular helmet attaches itself to Solgaleo's head, with two long horns rearranged from Necrozma's wings on both sides of the helmet. Two light blue eyes and nose are visible within the helmet. Necrozma's brain prism has been inserted inside the helmet and is visible as a multicolored triangle. Using the split tail on its sides, Dusk Mane Necrozma can propel forward using black light[1].
Dawn Wings Necrozma has the appearance of a Full Moon phase Lunala combined with parts of base Necrozma. Necrozma's head attaches to Lunala's chest in the form of black V-shaped armor with four glowing pink shapes visible underneath. Necrozma's arms are now attached to the lower part of the chest armor with the large crystals disappearing as well. The tail has now split in two and attached to Lunala's back. There are eleven crystalline spikes attached around the body: four each on the wings and three on Lunala's tail. On the front side of its head is a scalene triangular helmet with two bright pink eyes visible underneath. Necrozma's brain prism has been inserted inside the helmet and is visible as a multicolored triangle. Using the split tail on its back, Dawn Wings Necrozma can propel forward using black light[2].
Ultra Necrozma is said to be Necrozma's true form. It is a colossal dragon with parts of Necrozma's base form rearranged. Its body is made entirely of light that is produced from the brain prism, which is no longer visible. Ultra Necrozma has a long, spiked tail and a head resembling a shining star with three long horns on the sides and top. On each side of its head are two wing-like protrusions with another set of two smaller ones on the underside of its head. Both eyes contain a multitude of colors, though the left eye is primarily red while the right is primarily blue. In this form, Necrozma's arms have become Ultra Necrozma's feet. Its legs and feet have now become the top part of the upper set of wings connected to its shoulders while its feet have become the upper part of the lower set of wings connected to its hips. Its tail becomes a piece of chest armor while the star shaped symbol has now moved to the back of its head. Its head has now become a piece of armor attached to its face. As Ultra Necrozma, all of the pieces of Necrozma's base form have now become a shining golden color, though it will return to black if the light it has stolen escapes. Ultra Necrozma has a body temperature of 10,000 degrees Fahrenheit, which enable it to burn or melt through anything, with the laser's power increasing to a distance of 18 miles.[3]
Necrozma was discovered dwelling deep underground, where it had been asleep for ages, it was later discovered to have originated from Ultra Space. Due to the peculiar nature of its body, the power it wields, and the rumors that it came from another world in the distant past, it is speculated that it may be related to the Ultra Beasts, if it is not actually one itself; however, the International Police have no records of it ever emerging from an Ultra Wormhole so its classification is still uncertain. Despite being pitch-black, it constantly refracts light like a prism. Light acts as the source of its energy, and it can concentrate this light to fire lasers. When it absorbs light, its brain prism glows white[4]. It is known to be incredibly vicious, firing off laser beams at anything around it, while also appearing to be in pain while searching for light.[5]
Necrozma is capable of opening and traveling through Ultra Wormholes, though it can open up multiple Ultra Wormholes at once while in its Dusk Mane or Dawn Wings forms. Whenever Necrozma changes into its three different forms, it rearranges it body parts in order to adapt. The people of Ultra Megalopolis refer to Necrozma as the "Blinding One" (Japanese: かがやきさま Radiant One) as it once had the ability to give light, which affects and impacts all livings things and nature that come into contact with it. This light led to existence of Z-Power and the auras that surround Totem Pokémon when Necrozma shared it with the native beings of Alola. In its base form, Necrozma can control light, but lost the ability to create it after being injured under unknown circumstances thought to have involved the people of Ultra Megalopolis. In an effort to restore itself to its original state, it is compelled to steal the light from other places to sustain itself. Professor Kukui and Lillie theorize that the Sparkling Stones used to perform Z-Moves are fragments of Necrozma's body that it lost to the aforementioned injury.
Necrozma is the only known Pokémon capable of learning the moves Prismatic Laser and Photon Geyser, the latter of which can be upgraded into the exclusive Z-Move Light That Burns the Sky while in its Ultra Necrozma form. Dusk Mane Necrozma and Dawn Wings Necrozma can also learn Solgaleo and Lunala's signature moves Sunsteel Strike and Moongeist Beam, respectively, and upgrade them to their exclusive Z-Moves Searing Sunraze Smash and Menacing Moonraze Maelstrom.
Origin
Necrozma could be based off the concept of prisms and light refraction. Given the first part of its name ("necro"), its black coloration, and the star symbol on the back of its head, it could also be based off a black dwarf (which is a theoretical "dead star" that has ceased to emit light or heat), or given its ability to absorb light, it could also be based off a black hole (which is formed from a collapsed star).
Necrozma's Dusk Mane and Dawn Wings forms may be based on the concept of solar and lunar eclipses. The forms' alternate names in Japanese, 日食 nisshoku (solar eclipse) and 月食 gesshoku (lunar eclipse) can also be literally translated as "eating the sun/moon", reflecting how Necrozma absorbs Solgaleo or Lunala to assume those forms, as well as historical interpretations of eclipses as something stealing or eating the sun or moon. Its Ultra Necrozma form may be based on giant stars.
Name origin
Necrozma may be a combination of νεκρός nekrós (Ancient Greek for dead), 黒 kuro (black), and πρῖσμα prîsma (Ancient Greek for prism). It may also be based off of Project Ozma, an experiment made to search for extraterrestrial life.