The Wither

The Wither is a floating, three-headed, demonic boss mobwith a skeletal appearance and is Minecraft's secondary antagonist. It originates from the Nether and is the second boss mob introduced and added to the game after the Ender Dragon in 1.4.2 the Pretty Scary Update.

It can only be encountered and battled by being summoned by a player. It's also the only way to obtain the Nether star, which is used for crafting the beacon. The Ender Dragonhad the most health out of any mob in the game until the Wither was implemented.

Wither Storm

The Wither Storm is a mutated Wither found in Minecraft: Story Mode. It was created by building a Wither with a command block in place of the middle soul sand and it absorbs blocks and mobs to increase in strength

Ender Dragon

The Ender Dragon is a hostile boss mob that appears in the End dimension and is the final boss of the original Minecraft. The Ender Dragon is a large dragon that breathes fire, spits fireballs, and is able to fly with great ease and maneuverability.

Elder Guardian

The Elder Guardian is a mini-boss that only spawns underwater, inside of or near ocean monuments. It is a stronger version of the guardian.

         The Arch

The Arch-Illager has come to power using the Orb of Dominance, turning the Overworld upside down. Power is collecting in strange places, the undead are stronger and refuse to burn in the sunlight, and Illagers are raiding the countryside! -In-game Voiceover-

The Redstone Golem is a weaker version of the Redstone Monstrosity. It has two attacks, and is found in the Redstone Mines as the "boss mob". It appears in the Fiery Forge, Highblock Halls, and Obsidian Pinnacle as a mini-boss. It has no horns, no mouth, smaller size, and less redstone than the Redstone Monstrosity. It appears to be powered by a Redstone Block on its back, and one in each of its upper arms.

the redstone Monstrosity is a Boss in Minecraft: Dungeons. It appears in the Fiery Forge as an obstacle to the player. It has three attacks; it is a variant of the Redstone Golem. It appears to be made of stone and cobblestone, with redstone along its body. It has three yellow eyes, a visible mouth, and most noticably, two massive arms used for creating shockwaves. Once the player has exploded all the Redstone Cores, it appears to stop players from escaping the Forge.