1.2.1 is a major update to Java Edition released on March 1, 2012, which adds a new height limit of 256 blocks (changed from 128) as a result of the new Anvil file format, zombie sieges, and generated features including jungle biomes, wooden bridges in mineshafts, and desert wells. It also added new blocks and items – bottles o' enchanting, redstone lamps, fire charges, and chiseled stone bricks – and two new mobs, iron golems and ocelots.
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