King Silverfish is a boss of the Overworld in Minecraft: A New Start. It is a large silverfish with a golden crown with a ruby in the middle of it. It has 200 hp (100 full hearts).
The King Silverfish is summoned by collecting silverfish scales(S), golden ingots{G) and a ruby(R) to craft the Silverfish Amulet.

Right-clicking the amulet will cause the King Silverfish to spawn as long as there is a cave nearby for the boss to spawn in, you have defeated the Ender Dragon and have killed 50 silverfish. When the King Silverfish spawns, the Player gets Blindness and Mining Fatigue when entering the cave with the boss.
Swords don't work very well on the King Silverfish and decreases their durability faster. Neither do bows and arrows. However, pickaxes work very well on him.

King Silverfish spawns aggresive silverfish and does only melee attacks of 1 and a half hearts. Upon reaching 25% of his health, The King Silverfish seperates his head from his body and his body explodes into 23-27 silverfish (nearly 100 on hard mode and above).

Upon death, King Silverfish will drop his crown which will turn silverfish passive towards you (they will be hostile again when you summon him again). The crown will wear down like regular armour. He will also drop some potions of health and haste. Defeating King Silverfish again will make it possible to craft the Silverfish Charm.