A Shulker is a unique mob found in the game Minecraft. It is known for its ability to teleport and shoot projectiles called Shulker bullets. When a player gets too close, a Shulker will hide inside its shell and become invisible, making it challenging to defeat. Shulkers are primarily located in End Cities, which are structures found in the End dimension. They drop Shulker Shells upon defeat, which players can use to craft Ender Chests or create a special type of block called a Shulker Box that allows for portable storage.