Minecraft wiki entry for Development_versions, associated text: Nocturnal passive mobs which sleep during the day and are awake at night.
Drops nothing when killed.
Will run from the player.
They are about as fast as ocelots.
Can be bred with sweet berries.
The baby born will trust the player and not run away. [more information needed]
Can spawn with items in their mouth, like wheat and leather.
Will pick up dropped items with their mouth, and drop them if they find food instead.
May spawn wandering around villages at night. [more information needed]
Hunt chickens and rabbits.
Jump very high, can jump into fenced-in areas to hunt chickens.
Are attacked by wild wolves (but run faster).
Can curl up in a ball to sleep.
During daytime, seeks out a nearby area where the sunlight level is below its maximum value, indicating there is not direct sunlight on that block.
A white variant spawns in snowy taiga.