Snow Golem

A Snow Golem (previously known as a Snowman) is an upcoming mob which was first mentioned by Notch on September 21st, 2011 to appear in Beta 1.9. According to the tweets by Notch, a Snow Golem is a friendly mob. You will be able to craft Snow Golems, likely requiring the materials such as snow, pumpkins, coal, and sticks. Snow Golems will throw snowballs at enemy mobs and will melt in warmer biomes. As Snow Golems move, they leave a trail of snow on the ground.

Behavior
Snow Golems will not attack their creator. However, they will throw snowballs at hostile mobs, provoking them. This gives them an almost suicidal nature, because snowballs do no damage, but they attract enemies which can kill it or the player. It is unknown if Snow Golems will attack Passive mobs.

Crafting
Snowmen can be Crafted by Placing two snow blocks and a pumpkin in a vertical stack

Farming
Because Snow Golems create a constant blanket of snow on the ground as they move, it should be possible to farm it. However, due to the provoking nature against hostile mobs, the player may want to make sure they are in an enclosed space.

Furthermore, Snow Golems can be used to lure hostile mobs into mob traps. This could create a better flow of incoming items, as you won't have to wait for said mobs to wander in.

Trivia

 * Snow Golems are the first mob the player can create through the use of crafting.
 * Notch originally planned to call this mob Snowmen. However, very soon after revealing the name, he came upon the Reddit user "Cuttleman's" entry stating he would call them Snow Golems. He immediately decided to change their title to this.