1.4 is an update added to Minecraft, and it was known as the Pretty Scary Update.
- Added Wither (couldn't spawn without the use of mods or hacked clients)
- Change difficulty (/difficulty <new difficulty>)
- Change game rules (/gamerule <rule name> [value])
- Set a new spawn point (/spawnpoint [player] [<x> <y> <z>])
- Change the weather (/weather <clear/rain/thunder> [duration in seconds])
- doFireTick (when disabled, fire will not spread)
- mobGriefing (when disabled, mobs can't change blocks, pick up blocks, or destroy blocks)
- keepInventory (when enabled, a player will keep their entire inventory when they die and respawn)
- doMobSpawning (when disabled, mobs will not spawn)
- doMobLoot (when disabled, mobs will drop nothing when killed)
- doTileDrops (when disabled, blocks will not drop as items when they are mined)
- Villagers have a chance of turning into Zombie Villagers after being killed by a Zombie in Hard difficulty.
- Zombie Spawn Eggs have a chance to spawn Zombie Villagers
- Zombie Villagers can naturally spawn.
- Zombie Villagers can be cured, turning into a regular Villager.
- New "villages.dat" file in the data file of world saves.
- Villagers now react positively on new trades, and negatively if harmed by a player.
- Added an unused particle effect of a villager's face with an angry expression.
- Villagers will no longer remove trades, but making a new trade may be required to renew old ones.
- Zombies, skeletons, and zombie pigmen sometimes spawn wearing equipment such as enchanted weapons and any armor, depending on the level of difficulty.
- Added a zombie attack animation when it holds a weapon.
- Iron golems now attack slimes and magma cubes.
- Sheep from spawn eggs can now spawn naturally-colored sheep (white, gray, brown, pink, etc.).
- Mobs can go through portals.
- Stairs now auto-arrange into corners.
- Removed the (Beacon Block aka WIP block) wip block from the creative inventory.
- Added arrow-sensitive wooden buttons.
- Added working Night Vision Potion in Creative inventory.
- Leather armor can now be dyed.
- Item frames crashes fixed.
- Fixed /me command only working for ops.
- Fixed /tell command.
- The attribution of the quote at the end of the credits changed from "Mark Twain" to "Unknown".
- Easier to adjust maps.
- F3+P will toggle the auto-pause when the window loses focus (for debugging).
- F3+H will toggle detailed item descriptions (for debugging).
- Nether portal bugs fixed.
- Tweaked the "hidden feature".