Kyurem has two alternate forms, Black Kyurem and White Kyurem, which are formed by combining with Zekrom and Reshiram, respectively, and share many aspects of their designs with them. Their legs are just like Normal Kyurem's legs, but shorter and the middle toe is now ice; White Kyurem has some extra icy details on the legs. Their tails are just like Reshiram's and Zekrom's tails but they are attached to the body with three gray parts of skin. The tails seem to be fully able to move and contain four holes: they are vertical on Black Kyurem and horizontal on White Kyurem's silver rings. Their torsos are similar, but Black Kyurem's torso is more bulky than White Kyurem's torso, which is slim. Their shoulders are covered in 'squares' of ice with two pins protruding from each which can come out and 'plug in' the aforementioned holes. Their arms are quite different: Black Kyurem has Zekrom's arms, but more muscular and without wings, which are attached to the icy shoulders mentioned before, and its left arm and wing are frozen; White Kyurem 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. Their necks are the same shape, and are long like Normal Kyurem's but now upright; Black Kyurem uses Zekrom's skin and White Kyurem uses Reshiram's fur. In both forms, the ice covering one of Kyurem's jaws (lower for Black Kyurem, upper for White Kyurem) has partially disappeared, allowing it to move its mouth properly.
Also, Kyurem-W gets it's ability Turboblaze from Reshiram
When fusing, Kyurem-W will take all EVs/IVs/Nature from Kyurem rather than Reshiram
It's base stats are influenced by both with Offense coming off Reshiram and Defense/Speed more off Kyurem. I think they also share movepools....