/summon minecraft:slime ~ ~1 ~ {Size:0,CustomName:"Slime asesino ",CustomNameVisible:1,Attributes:[{Name:"generic.followRange",Base:500},{Name:"generic.knockbackResistance",Base:1f},{Name:"generic.movementSpeed",Base:4f},{Name:"generic.attackDamage",Base:1000000}],Invulnerable:1}