Armor Stand

Armor Stand is an entity rather than a block, and everything odd about it follows from that. It falls when you remove the ground under it, a piston will push it, fire and lava destroy it, and hitting it knocks it back into an item along with everything it was wearing — so an armor stand display belongs somewhere a stray swing cannot reach.

Using one is simple: hold a piece of armor and use it on the stand to dress it, then take the piece back the same way. It will wear a full set, a mob head, a carved pumpkin or an elytra, which makes it the standard way to park a spare kit where you can see it rather than lose it in a chest, and the only way to show an elytra off without wearing it. The one part of the recipe that trips people is the slab: it has to be smooth stone, which means smelting cobblestone into stone and then stone into smooth stone before cutting it.

Poses are where the editions part company. In Bedrock Edition an Armor Stand has arms, holds items in them, and cycles through thirteen fixed poses driven by a redstone signal — that signal is the basis of the dancing armor stand builds people share. In Java Edition the plain stand has no arms and no pose control without commands, so an armed, posed stand there is a command job rather than a crafting one.

Facing is set when you place it, so stand where you want it to look before putting it down rather than trying to turn it afterwards. It sits on any solid surface, slabs and stairs included, and because a piston can shove one without breaking it, armor stands are a simple way to make something appear to walk, rotate or rise out of a floor in a redstone build.