This Pocket Edition-exclusive block was the original answer to adding the Nether.
Nether Reactor Core
This update has the unique trait of being released in two separate parts.
1.17 / 1.18 / Caves and Cliffs
This variant of the Zombie, unlike its brethren, does not burn in sunlight.
Husk
Before the Pale Forest, falling leaf particles were exclusive to the trees in this biome.
Cherry Grove
Bundles used to be crafted using this item before it was changed to leather.
Rabbit Hide
This block is the only solid, breakable block that generates in all 3 dimensions.
Obsidian
This update was big for Jukebox fans, as it added the first music disc since 2012.
1.16 / The Nether Update
This passive mob has a larger selection of variants than any other mob in the game.
Tropical Fish
Despite losing the Biome Vote in 2019, this biome still got some love in the Wild Update a few years later.
Swamp / Mangrove Swamp
White Tulips are able to be crafted into this dye colour.
Light Grey Dye
Despite having "Stone" in the name, this terrain block cannot be used to craft stone tools.
End Stone
This April Fool’s update took things in a new direction by adding a grappling hook.
24w14potato / Poisonous Potato Update
Vindicators will go on a rampage, attacking nearly all mobs nearby, when given this name.
"Johnny"
A rare safe haven for players, this is the only surface biome in the game where no hostile mobs can spawn.
Mushroom Fields / Mushroom Islands
The Dried Ghast can actually be crafted, using 8 Ghast Tears surrounding this block.
Soul Sand
While obsidian is required to craft this block, it does not need a diamond pickaxe to be mined.
Beacon
This recent update finally added the long-wanted feature of craftable saddles.
1.21.6 / Chase the Skies
Before villagers were added, villages were to be inhabited by this mob.
Pigmen
In the Nether, Skeletons can only spawn in Nether Fortresses or this biome.
Soul Sand Valley
This block's crafting recipe was recently modified, now using iron to craft instead of netherite.
Lodestone
This block has an outdated variant that is currently only available in old versions of the game, and the New Nintendo 3DS version.
Stonecutter
This update was the first to include a mob chosen by a Mob Vote.
1.13 / Update Aquatic
This mob has the unique trait of donning a specific texture upon being renamed.
Rabbit
All ocean biomes in the game have both a standard and a deep variant, except for this one.
Warm Ocean
Chainmail Armor used to be craftable using this now-removed item.
Fire