Gigantic slime boss by char

Summon the Slime boss with a egg Loot?

This is the egg version:

/give @p spawn_egg 1 0 {EntityTag:{id:Slime,Size:23,Attributes:[{Name:"generic.maxHealth",Base:185},{Name:"generic.followRange",Base:70},{Name:"generic.knockbackResistance",Base:0.05f},{Name:"generic.movementSpeed",Base:1f}],HandDropChances:[2F,2F],HandItems:[{id:"minecraft:spawn_egg",Damage:55,tag:{display:{Name:"Slime Egg",Lore:["These is really are pieces of slime."]}},Count:64},{}]}}