Wolf

Wolves are new mobs set to appear in Beta 1.4. Notch has confirmed the addition of these animals upon having breakfast with Peter Molyneux. On March 18th, 2011, a video was posted showing a preview of wolves, which are being made by Jeb. Wolves will spawn in forest and taiga biomes. Wolves can swim, and will shake water droplets off of their bodies when exiting water. Wild wolves are usually neutral. Wolves may also be considered the "pet dogs" as previously mentioned by Notch.

Taming
They are said to be rather rare, but they will not despawn once tamed. To tame a wolf, you must feed it bones until a puff of heart particles appears, which indicates that the wolf has been tamed. The number of bones required is random.

Once tamed, they will become friendly. They will now protect you, and go by your commands. You can attack a mob and then they will attack it as well by jumping at it. They will also follow commands such as sit, eat, and possibly more.