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.

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.

Tamed wolves can be identified by a friendlier facial expression and a bright red collar around their neck. They will follow the player around, and will attack anything that the player melees or is attacked by. It should be noted that tamed wolves will not attack anything you hurt with arrows.

Once tamed, they will be turned into dogs and will protect you, and go by your commands. Such as sit, or attack.