Corrupted Ghast

Corrupted Ghasts are the Blackdown variation of Ghasts. Unlike most Blackdown Mobs, this blackdown mob is a boss with the health of an enderman. This boss mob can be summoned with an Eye Of Ghast. After the eye is used, the boss is summoned. In battle, you cannot normally hurt this thing. You have to get it's fireballs in it's mouth while it's attacking. This reveals its core. Once the core is open, spam attacks at the thing for massive damage before it closes!

Ghastly Dive
Damage: OHKO if thouched

First, the boss prepares to lunge at the player, and lunges with its mouth open. You get hit by this by touching this bosses mouth. When you get hit by this, it's an OHKO, as you get eated to death.

Haunted Grab
Damage: 60 hearts.

The thing grabs you and damages you. Nuff said about this attack.