Oak Trapdoor
A wooden trapdoor is a variant of the trapdoor that can be opened and closed by the player without redstone.
Oak Hanging Sign
A hanging sign is a variant of a sign that displays text, and can be placed underneath blocks or with a solid self-supporting bracket. The text of hanging signs can be customized with dyes and glow ink sacs, and they can be waxed to prevent edits.
Oak Sign
A sign is a non-solid block that can display text, and can be placed on the top or side of other blocks. The text of signs can be customized with dyes and glow ink sacs, and they can be waxed to prevent its text from being edited by any player.
Oak Wood
Wood or hyphae is a block that has the log's "bark" texture on all six sides. It comes in 11 types: oak, spruce, birch, jungle, acacia, dark oak, mangrove, cherry, crimson, warped, and pale oak.
Observer
An observer is a block that emits a quick redstone pulse from its back whenever its "face" detects that the block, fluid, or air directly in front of it has changed.
Obsidian
Obsidian is a block found naturally in all dimensions, and created when water flows over a lava source in the Overworld, or as part of structures in the Nether and the End. It has high hardness and blast resistance, making it immune to normal explosions. Obsidian can be used to craft beacons, enchanting tables, and ender chests, and build the frame of a Nether portal. Obsidian is only obtainable with a diamond or netherite pickaxe.
Ocelot
An ocelot is a trustable passive mob found in jungles. They run away from nearby players, but their trust can be gained by feeding them raw cod or raw salmon. Creepers, as well as phantoms in Bedrock Edition, stay away from ocelots.
Ocelot Spawn Egg
A spawn egg is an item used to instantly spawn mobs.
Ochre Froglight
A froglight is a light-emitting block that is obtained when a frog eats a tiny magma cube. It comes in three variants based on the variant of frog that eats the magma cube.
Ominous Bottle
An ominous bottle is an item that gives a player the Bad Omen effect for 100 minutes when drank, which can cause an ominous event to start.
Ominous Item Spawner
Ominous item spawners are entities spawned by ominous trial spawners that display an item for 3 to 6 seconds before dispensing it downwards.
Ominous Trial Key
An ominous trial key is a type of trial key that can only be obtained from ominous trial spawners. It is used to unlock an ominous vault and obtain its loot.
Open Eyeblossom
An eyeblossom is a unique flower found in the pale garden biome. It changes state depending on the daylight cycle, closing during the day and opening at night. Its "eye", visible only when the flower is open, glows in the dark but does not emit light in its surroundings.
Orange Banner
A banner is a block that can be crafted in 16 different colors, customized in a loom using dyes and banner patterns, and applied to a shield. In Java Edition, banners can also be used to add markers to maps.
Orange Bed
A bed is a dyeable utility block that allows a player in the Overworld to sleep through the night and reset their spawn point to within a few blocks of the bed, as long as it is not broken or obstructed.
Orange Bundle
A bundle is an item that can store up to a stack's worth of mixed item types within itself in a single inventory slot. Items can be individually selected and taken out of the bundle via the inventory menu. Dyed bundles are the dyed variants of bundles.
Orange Candle
A candle is a dyable block that emits light when lit with a flint and steel. Up to four of the same color of candle can be placed in one block space, which affects the amount of light produced. Dyed candles are the dyed variants of candles that come in all sixteen colors, that once dyed, cannot be changed into a different color.
Cake with Orange Candle
A cake is both food and a block. It can be eaten by placing and using it, with each use consuming one of its seven slices. A cake with candle is an uneaten cake with any type of candle placed on it, which can be lit with a flint and steel to emit light.
Orange Carpet
Carpets are thin variants of wool that can be dyed in any of the 16 colors.
Orange Concrete
Concrete is a block created when concrete powder touches water. It comes in the sixteen dye colors.
Orange Concrete Powder
Concrete powder is a gravity-affected block that is converted to concrete when touching water. It comes in the sixteen dye colors.
Orange Dye
Orange dye is one of the sixteen available dyes.
Orange Glazed Terracotta
Glazed terracotta is a vibrant solid block that comes in the sixteen regular dye colors, obtained by smelting stained terracotta. Glazed terracotta does not stick to slime blocks or honey blocks, and it cannot be pulled by sticky pistons, but it can be pushed by pistons.
Orange Harness
A harness is an item that can be equipped on happy ghasts to make them mountable and rideable. Harnesses can be crafted into 16 dyed variants.