Kyurem did not originate from fanon, and the information on this page may not be entirely accurate to their canon. You may read more about this subject in the context of their canon on the following wiki(s):
Kyurem (Japanese: キュレム Kyurem) is a dual-type Dragon/Ice Legendary Pokémon.
While it is not known to evolve into or from any Pokémon, it has two other formes, which are activated by using the DNA Splicers on it and either Reshiram or Zekrom, resulting in a process called Absofusion that removes Reshiram or Zekrom from the party until the fusion is undone. It will then become White Kyurem (with Reshiram) or Black Kyurem (with Zekrom). However, it is impossible to own a White Kyurem and a Black Kyurem at the same time, as the game rejects the second fusion of Kyurem with Reshiram/Zekrom.
Along with Reshiram and Zekrom, Kyurem is a member of the Tao trio, which exists in the legends of the Unova region.
As both Black Kyurem and White Kyurem, it is the version mascot of Pokémon Black 2 and White 2, respectively.
Kyurem is a gray and blue, bipedal Pokémon of indefinable but seemingly draconic basis. Kyurem has a blue head and snout and has yellow eyes without pupils, has a pair of pointed light bluish horns on its head and a yellow crest on its skull. Three pointed teeth jut out the bottom of either side of its jaws, which are frozen shut by the ice covering its head. Its long, gray neck has lines running around its whole body, legs, arms and tail. It has two arms, each with its own claw and each arm is jointed together from its oddly shaped blue wings, which are believed to be used for flying and storing cold air. Each wing has two spikes of ice. The ice covering the wings can break, revealing gray tendril-like appendages on Kyurem's back. The right side of its body seems to be damaged in some way, as the wing and horn on its head on that side are shorter; the right side of its head also has a spiked edge near its jaw hinge that is absent from its left. Its legs are somewhat slender, and has three sharp ice-like claws on each enormous foot. Its tail has three blue conical spikes on its tip, and appears to be some sort of propulsion device or a container of energy; exactly what it is based on is unclear, but it may be a damaged turbine.
Kyurem has two alternate forms, White Kyurem and Black Kyurem, which are formed by combining with Reshiram and Zekrom, respectively, and share many aspects of their designs with them. It can use Absofusion on their respective Dragon Stones to change to White or Black Kyurem. When transformed into either, its legs are just like before, but shorter and the middle toe is now ice. As White Kyurem, it has some extra icy details on the legs. Its tail resembles that of Reshiram or Zekrom, but they are attached to the body with three gray parts of skin. The tail is capable of movement and contains four holes: they are horizontal on White Kyurem and vertical on Black Kyurem. The torsos of each form are similar, but White Kyurem's torso is more slim than Black Kyurem's bulky torso. Its shoulders are covered in 'squares' of ice with two pins protruding from each which can come out and 'plug in' the aforementioned holes. As White Kyurem, it has thin arms with two rings and three claws each, wings between the rings on its forearms, and its right arm and wing are frozen. As Black Kyurem, it has Zekrom's arms, but more muscular and without wings, and its left arm and wing are frozen. Its neck is the same shape, but is now upright; White Kyurem uses Reshiram's fur and Black Kyurem uses Zekrom's skin. In both forms, the ice covering one of Kyurem's jaws (upper for White Kyurem, lower for Black Kyurem) has partially disappeared, allowing it to move its mouth.
Kyurem generates a powerful, freezing energy inside itself, but its body became frozen when the energy leaked out. Due to an old legend, it may be assumed Kyurem may be hostile towards Pokémon and humans, due to the fact it supposedly ate them if they were found outside at night. Kyurem is an extraterrestrial Pokémon. It is the only Pokémon that can learn Glaciate, while its alternate forms White Kyurem and Black Kyurem can respectively learn Ice Burn and Freeze Shock instead. White Kyurem and Black Kyurem can also learn Reshiram's and Zekrom's signature moves Fusion Flare and Fusion Bolt, respectively.
Minimum stats are calculated with 0 EVs, IVs of 0, and a hindering nature, if applicable.
Maximum stats are calculated with 252 EVs, IVs of 31, and a helpful nature, if applicable.
No other Pokémon has the same type combination as Kyurem.
White Kyurem and Black Kyurem have the highest base stat total of all Ice-type Pokémon.
White Kyurem has the highest Special Attack of all Ice-type Pokémon. Black Kyurem has the highest Attack of all Ice-type Pokémon.
White Kyurem is the tallest Ice-type Pokémon and the tallest Pokémon introduced in Generation V.
Unlike most Pokémon with no evolutionary relatives, Kyurem can learn a move—Imprison—twice with neither instance being at level 1. It shares this trait with Plusle, Palkia, Smeargle, Reshiram, and Zekrom.
Kyurem is the only Pokémon with a base stat total of 660.
Kyurem is the only member of the Tao trio that cannot learn its respective Elemental Fang.
Although several Pokémon are the result of two or more individuals combining (Dugtrio, Slowbro, Slowking, Magneton, Metang, Metagross, Weezing), White Kyurem and Black Kyurem are the only ones to be shown doing so in the core series games. They are also the only fusions that are not part of a Pokémon's evolution and are the only fusions which have been shown to be reversible.
Kyurem is the only Pokémon to be the version mascot of both versions of a paired version.
Despite being larger when fused, both fused forms are lighter than the Pokémon it's fused with.
Kyurem has the most separate cries used in-game, with five. It has one for each forme and two longer cries that play in stereo.
Kyurem is the only Pokémon that can fuse with another Pokémon.
White Kyurem and Black Kyurem cannot be deposited into Pokémon Bank.
Kyurem and its two counterparts Reshiram and Zekrom are based on the concept of yin and yang in Taoism. Kyurem, however, symbolizes wuji, the absence of yin and yang. In regards to overall design, it appears to be based on a theropod and a European dragon, similar to Zekrom. Its arms in particular seem to be influenced by Tyrannosaurus rex. Kyurem's type, Ice, may allude to the absence of energy and the concept of absolute zero. Kyurem's rock-like body and its origin story of arriving on Earth like a meteor are references to comets, which are largely composed of ice crystals.
Given that its Japanese name contains mu, it may be based on the koan mu.
Kyurem may be a combination of 冷 rei (cold), 急冷 kyuurei (rapid cooling), or 雪 yuki (snow) with the kana reversed, and 無 mu (nothing). It may also derive from 零 rei (zero). Rem may also mimic the rom of Zekrom and the ram of Reshiram.