Horse

Horses are a planned 1.6 mob hinted by Jeb when Minecraft hit 10,000,000 sales. DrZhark, creator of the Mo' Creatures mod assisted with the horse's creation, which is the same from Mo' Creatures.

Once a horse is tamed and a horse saddle is attached, they can be controlled with standard directional controls and the mouse. Different variations of horse armor can be put onto horses. They can be tied to fence posts using a leash. There are different breeds of horses, similar to the different breeds of cats. A foal's growth can be accelerated via the use of apples, wheat, sugar, bread, hay bales. Horses are completely passive when hit.

Appearance
There are currently 5 variations of the horse mob in the game, 2 of which spawn naturally in the wild. The normal horse are all the same breed and can be 1 of 7 base colors; gray, dapple gray, dark bay, bay, flaxen chestnut, buckskin, and black. The horses also have a secondary coloring known as markings. There are 5 different markings; no markings, stockings, snowflake appaloosa, pinto, and black blanket. In total there are 35 possible horse color combinations taking into consideration all base colors and markings. There is also the donkey which can be bred with a horse to produce the mule. There are two types of undead horses: a zombie horse and a skeleton horse, but they cannot be tamed by the player, and can only be brought into the game by editing the region files.

Horses
Horses are the regular horse breed in the game, and occasional foals will spawn too. They can wear horse saddles and can wear any horse armor. Foals can be fed to grow faster, see table below.

Mules and donkeys
In Minecraft, donkeys are a variation of horses, which spawn less commonly than normal horses. Young donkeys and mules can be fed apples and sugar in the same manner as horses. They can wear a horse saddle, but not horse armor. Instead, they can wear a chest, but the inventory is not accessible (yet). Upon death a donkey or mule will drop the attached chest. As in the real world, mules can be produced by breeding a horse with a donkey, which seems to work more rarely than normal breeding of two horses or two donkeys. Mules themselves cannot breed.

Skeleton
A skeleton variation of a horse. It does not appear to be tameable. It has only one texture and cannot equip anything. It can only be spawned through third party editing programs at this time.

Undead
A zombie variation of a horse. It does not appear to be tameable. On the texture they have more of a leather pack than a chest. It can only be spawned in through third party editing programs at this time.

Taming
To tame a wild horse, approach it and right click on it with an empty hand. You will climb on top of it, and will likely be thrown off. After a few attempts, it will allow you remain on it and will give off heart animations. At this point you can dismount it by pressing the Sneak key and place a horse saddle on it.

The chance of successful taming on the first try is 0%. Every failed attempt increases this chance by 5. This means that on the second mount the player has 5% chance of success; on the third - 10% etc. Taming can be sped up by feeding the horse any of the approved foods when you are standing next to it - see column "Taming prob." in the table above.

Riding
Once you have tamed a horse and put a horse saddle on it, you can control it with standard directional controls and the mouse. Horses can be made to jump, and holding the jump key allows you to charge your jump. Horses are not affected by Jump Boost beacons. Sneaking causes you to dismount, as does going in water deeper than two blocks.

When you mount a horse, the hunger bar and oxygen bar are replaced by the horse's health in survival or adventure mode. It uses a slightly different heart texture than the player's health bar. The experience bar is replaced by the horse jump bar, which gauges how high you jump. The maximum jumping height, which is reached when the bar is fully charged as you release the spacebar, depends on the horse you ride. It seems to range from about 1.2 to 5.1 blocks high. As each horse has different statistics, it is difficult to gauge the maximum distance but testing has revealed that certain horses can jump distances of 11 blocks.

You can use any item while riding a horse, including drinking or throwing potions, activating doors or redstone devices, or using chests, crafting tables, and furnaces. You can also break and place blocks and attack.

When running forward, you will start at a slow walk and build to a speed faster than sprinting. You will automatically run up any one block high slope. You are three blocks tall while on a horse, but you can ride under 2 block tall areas, causing your head to pass through blocks. This causes suffocation damage, except when passing through non-solid blocks. You are slightly wider than one block, and are unable to walk through one block wide gaps. However, due to the horse's length, you can run over any one block gap. It also appears you can run across a two block gap at high speeds, but this does not seem to work all the time. You can also cause your horse to climb ladders by running at it similar to how players climb them.

Virtually all horses appear to be able to outrun a mine cart when both are moving at full speed. Some seem to be quite dramatically faster than a mine cart. This can be combined with speed potions and the Nether to make the horse easily the fastest practical way to travel in Minecraft (around 130 m/s Earth-equivalent in The Nether).

Horses are very slow moving backwards, and about as fast as the player when moving sideways. Therefore, turning around is quite preferable to moving backwards or sideways.

Breeding
Horses are bred by feeding them wheat while you're riding them, but they cannot breed if they're wearing armor.

The new foal takes one of the colors and one of the markings of its parents the majority of the time. On rare occasions however, an offspring may be produced with a color or pattern that matches neither of the parents'.

Once you have bred two horses you have a chance that the offspring is going to have better properties like having more health, better speed or jump strength.

Offspring healthbar always shows 26 hearts even though its real hp is lower (and never exceed 15 hearts). This glitch can be fixed by reloading the world.

Trivia

 * An interesting trick you can do while riding a horse is to get on your horse, press F1 on your keyboard, drink a potion of invisibility, and press F5. It will look like you are the horse, instead of riding on the horse.
 * This can be used to trick other players that you are a horse, so they probably wouldn't recognize you, which makes horses a great mob disguise.
 * This also works with pigs, but you can only control it with a carrot on a stick, making other players see you holding an item when you are invisible.
 * It is possible to jump over wooden fences at the full jump boost (in yellow zone)
 * Upon death of a tamed and saddled horse, the horse will drop a regular saddle. This is most likely a bug.
 * Horses can have special abilities using potions such as Potion of Swiftness, Potion of Regeneration, Potion of Fire Resistance and Potion of Invisibility
 * Horses do not have a sound for right now, but still open their mouths as if they were.
 * Even though the skeleton and zombie horses look like undead versions of their counterparts, they are not treated as undead. A Wither will attack them as if they were any other non-undead mob.
 * Running over a TNT-cart landmine, even a very powerful "Nuclear minecart" one on a horse will result in the horse dying, but the player being undamaged... until they hit the ground!
 * Horses are quite possibly the best method of travelling long distances over-land, they can attain speeds of at least 11 meters/second (660 blocks per minute, nearly 40 km/hour), deal with normally jump-requiring terrain very easily, jump ravines with near-100% consistency, and require no infrastructure except at the ends (they are not good in jungles or some forests though.)
 * Horses do not breed with armor, making it so that armored horses can no longer breed, as armor cannot be removed.