King Slime can be faught and killed in Pre-Hardmode and Hardmode.It can be summoned using a Slime Crown made from 30 gold bars and 1 ruby at an anvil.King Slime has a 1:300 chance of replacing a slime.It can spawn in the Underworld or on the Surface. It has 2000 health and shrinks as it spawns out blue slimes to attack you.