Mob

Mobs are the various types of creatures and monsters found in Minecraft. Currently, there are 14 unique mobs although alternative mobs can be implemented by mods. Mobs are affected by the same environmental hazards as the player, including burning and collision (falling) damage, with the exception of chickens, who do not suffer collision damage. Mobs can see you up to 16 blocks away, except for the Ghast which can see you 100 blocks away. Up to 200 hostile mobs and 15 neutral mobs can be on a map at a time. Mobs spawn no closer than 24 blocks from the player. Sometimes the player will find lots of passive mob at night around a few torches because they spawn in light. This is also a tactic to mine mob drops.

The term "mob" is short for "mobile" and has been used as a general term referring to any moving entities in games since the first MUDs surfaced.

About
As of Beta, there are a total of 14 types of mobs: Wolves, Pigs, Sheep, Cows, Chickens, Squid, Zombie Pigmen, Spiders, Zombies, Skeletons, Creepers, Slimes, Spider Jockeys and Ghasts. More information is listed below.

Current Mobs
Allied

Allied mobs follow players around and protect them after being tamed.



Wolf

Passive

Passive mobs will never attack the player.

Require a light level of 9 or higher to spawn with the exception of Squid.

Neutral

Neutral mobs will not attack the player unless provoked.

Aggressive

Aggressive mobs will attack the player when in range.

Require a light level of 7 or less to spawn with the exception of Ghasts and Slimes.

Unused and Removed Mobs
Unused

Unused mobs are mobs found in the source, but are not being used at this time.

Removed

Removed mobs are mobs that have been removed from the game.

Potential Future Mobs
There are hints that new mobs might be released in the distant future. Below is the list of mobs that have been mentioned by Notch at least once and have a possibility of appearing in the game.

Giants have the zombie skin instead of the normal character's skin. It is possible Giants may become a future mob, although Giants are still hidden in the code and it is only possible to spawn them with mods or a map editor. Giants will hurt the player, but only if the player walks into the giant's body, otherwise it will simply push the player. Giants have 100 health and have an attack strength of 7½. Despite having the same skin as zombies, they make human sounds when hurt and they do not burn in sunlight.
 * Aside from zombie pigmen, living pigmen have been confirmed to appear in a future update.
 * In the Halloween update, Notch said he would add fish. However, he had limited time, and was thus only able to add them as an item. There is coding for fish in the game, but no model exists at this moment.
 * Dragons - Notch hinted during the Spider-Jockey update that he will add Dragons to the game. Dragons may also be able to fly or breathe fire. Notch confirmed on his Twitter that he will definitely add a form of flying transportation. There is a chance that Dragons may be able to be ridden in a similar manner to pigs.
 * Notch confirmed during the Brocraft.net stream that he will be adding prefix mobs. This means that there will be mobs such as 'Burning Spider' 'Giant Zombie' 'Cobble Creeper', etc. It is not known if these are still planned to be in a future update.
 * A "scary monster" is planned to appear in the 1.7 update.
 * Bats - Notch has briefly mentioned coding bats; however, not much has been mentioned about them since.
 * Giants - [[Image:Giantzombie.png|left|80px]]Notch briefly ran a test of giant zombies during the very first version of survival.

On the 13 of January 2011, Notch added Squids, a passive mob that spawns in water. It is likely that more water mobs will be introduced, as Notch stated on his blog that more water content was incoming.
 * Sea Monsters - On July 21, 2010, Notch commented via Minecast that Sea Monsters are a possibility. Particularly, he noted the possibility of sharks, but has recently stated that he would not be releasing sharks as it would be too difficult for the players to deal with. Whales have recently been confirmed as a sea mob, although their purpose hasn't been specified. Notch also confirmed on January 3rd, 2011 via his blog, that he will add a new water mob.
 * Boss Monsters - There is a possibility of boss monsters for the player to slay.

Trivia

 * The Halloween update version 1.2.0 (Alpha) allowed hostile mobs to spawn in higher light levels at lower depths, using the formula 16 - (Layer ÷ 8). At level 8 and below, mobs could spawn even in sunlight. Notch reverted mob spawning to the original method in version 1.2.1 (Alpha) saying, "It was far too annoying. I have plans on what to do with this."
 * When mobs spawn, smoke comes out of them.
 * Both neutral and hostile mobs' noises can be heard up to 16 blocks away, which is the same distance that hostile mobs can sense you. Therefore, if you hear a hostile mob, you can already assume that they have spotted you.