Overmind

The Overmind is a large, four-headed creature that spawns Ghasts, Blazes, Endermen, and Wardens. It has 500 HP on Java edition and 1,000 HP on Bedrock edition. They only spawn in the overworld. Overminds can be spawned into the world by using either the "/summon" command, or by using spawn eggs. They are the only way that ghasts and blazes can spawn naturally in the overworld.

Appearance:

The overminds are very large stationary creatures with four heads atop long, neck-like stalks.They have unseen tendrils anchoring them to the ground below. Due to their size, they may be easily visible from your home, even at low render distances!

Threat:

While the overmind is harmless, it can deal severe amounts of damage if you get close to it, even being capable of KILLING unarmored players!

How to kill:

It is recommended that you use either crossbows or splash potions of damage. Swords can be used, but you're usually at risk of being killed if using swords. Tipped arrows of damage would work best. Zoglins would work well too. Unlike other bosses, the Overmind's health-bar would be green.

Loot:

4-32 Bottles o' enchanting

1-8 Enchanted books (with randomized enchantments)

1 Overmind Brain (for each head destroyed)

...and lots of other endgame items...

Notes:

If you're standing near an overmind, clocks and compasses become useless and beds explode. Any villagers who get near an overmind would get brainwashed and turn into a new mob: infected villagers.