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. Baby horses' growth can be accelerated via the use of apples, wheat, sugar, hay bales, and are completely passive when hit, unlike other mobs.

Appearance
There are currently 5 variations of the horse mob in the game. The normal horse are all the same breed and can be 1 of 7 base colors; white, gray, dark brown, creamy, chestnut, brown, and black. The horses also have a secondary coloring known as markings. There are 4 different markings; white field, white dots, white, and black dots. In total there are 35 possible horse color combinations taking into consideration all base colors and markings (also noting a horse can be just a base color with no markings). There is also the donkey which can be bred with a horse to produce the mule. There are two other 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 and foals
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 apples, wheat and sugar to grow faster, however sugar grows them a little less than an apple.

Mules and donkeys
Donkeys are a different variation of horses, and are less common than horses when spawned. 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). Mules can be made by breeding a horse with a donkey, which seems to work more rarely than normal horse and donkey breeding. Mules themselves do not appear to be able to breed.

Skeleton
It is a skeleton variation of a horse. It does not appear to be tameable. Has only one texture and cannot equip anything.

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.

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 likely be thrown off. The taming appears to be sped up by feeding the horse any of the approved foods (apples, wheat, sugar), but only whilst on the horse, before it throws you off. After a few attempts, it will let you remain on it. At this point you can dismount it by pressing the Sneak key and place a Horse Saddle on it.

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. You are able to jump on to any four block structure with or without the effect, when the jump is fully charged. 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. 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.

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. This also allows you to heal your horse with a carrot while you ride it.

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.

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 riding on the horse.