As you already know you cannot summon the King Slime, like you can with Skeletron, The Eye, and The Eater of Worlds. But, i have a question for you all. Don't you think they should allow you to summon the King Slime? Once you collevt something like 100 gel, you can go to a demon altar or even a workbench,or furnace, and create an item that can summon the King Slime, maybe somthing called "King's Gel."
Tell me what you guys think.