Snowball

Snowball is an item that was added during the Minecraft Alpha 1.0.5 update. They are obtained when a snow block (4 snowballs obtained) or snow (1 snowball obtained) is destroyed with a shovel (as of the 1.0.5_1 update). They can be stacked up to 16 snowballs. They are a throw-able item that does not do any damage, but still knocks back mob and gives the same effect as if it was damaged. This makes it useful for herding and useful for knocking creepers off of high areas. Hitting sheep will even shear the sheep making it an effective way to get wool without hurting the sheep (although using a fishing rod may be better). Snowballs cannot be placed, they can only be thrown. Snowballs can be combined to make a snow block.

Trivia

 * Before the Seecret Saturday Update 1, you could get more than 4 snowballs from each block
 * Sometimes, you can see Ghasts in the Nether actually shooting a snowball.
 * Similarly, Ghasts on Earth shoot flaming snowballs.
 * Ghast fireballs are most likely edits of snowballs, as evident from the facts above.