While it is not known to evolve into or from any Pokémon, it has two other forms, 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 legitimately, as the game rejects the second fusion of Kyurem with Reshiram/Zekrom, and Kyurem cannot be traded or placed in Pokemon Bank while fused.
Along with Reshiram and Zekrom, Kyurem is a member of the Tao trio, which exists in the legends of the Unova region.
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. It is said to be an extraterrestrial Pokémon according to folklore. Kyurem 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.
Kyurem, in all of its forms, made its debut as one of the stars of Kyurem VS. The Sword of Justice, along with Cobalion, Terrakion, Virizion and Keldeo. Kyurem was challenged by Keldeo, who wasn't ready to fight Kyurem, but arrogantly claimed that he was a Sword of Justice. After the terrified Keldeo fled during the middle of the fight, Kyurem relentlessly pursues Keldeo in order to finish the battle they had started. Along with the other Legendary Pokémon present in the movie, Kyurem can speak through telepathy.
Kyurem reappeared in The King Returns, this time under the control of Ghetsis. It was used as part of his final attempt to freeze Unova, but was challenged by N and his Reshiram. However, Ghetsis used the DNA Splicers to fuse the two Pokémon into White Kyurem. It was last seen being challenged by Hilbert and his Zekrom.
Kyurem appears in its Normal Form as a Master Ball Pokémon. Upon summoning, it releases Icy Wind from its sides to freeze any caught opponents.
NA: While this Dragon/Ice-type Pokémon is definitely a Pokémon, some believe it is what remained after Reshiram and Zekrom were split apart. In battle, it will generate incredibly cold energy and then unleash it using Icy Wind. This move will deal constant damage before freezing opponents.
PAL: Kyurem is thought to be an empty shell left behind when Reshiram and Zekrom split into two. Its icy energy is so powerful that it can freeze its own body. When Kyurem has built up enough energy, it can unleash Icy Wind, shooting spirals of cold left and right. After damaging fighters, this attack with leave them frozen.
White Kyurem is the tallest Ice-type Pokémon and the tallest Pokémon introduced in Generation V.
Normal Kyurem is the only Pokémon with a base stat total of 660.
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.
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 form and two longer cries that play in stereo.
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 koanmu.
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.