The Spiked Slime is an enemy summoned by the King Slime boss in Expert Mode. They are summoned alongside Blue Slimes by the King Slime, and become more common as the boss loses health. They have the ability to shoot spikes at the player, just like the Spiked Ice Slime and the Spiked Jungle Slime.
- As they are exclusively found as part of the fight with King Slime, they are similarly unaffected by Royal Gel's immunity, and will continue to fire projectiles and damage the player on contact.
- Although it is normally impossible to encounter a Spiked Slime on a normal world (without external modifications), it will still have 50 HP instead of 100 if one manages to spawn it inside a normal world.