/summon minecraft:wither_skeleton ~ ~1 ~ {CustomName:"Slenderman ",CustomNameVisible:1,Health:800,Attributes:[{Name:"generic.followRange",Base:495},{Name:"generic.knockbackResistance",Base:0.17f},{Name:"generic.movementSpeed",Base:0.5f},{Name:"generic.attackDamage",Base:5}],ArmorItems:[{id:"minecraft:leather_boots",Count:1,tag:{display:{color:0}}},{id:"minecraft:leather_leggings",Count:1,tag:{display:{color:0}}},{id:"minecraft:leather_chestplate",Count:1,tag:{display:{color:0}}},{id:"minecraft:skull",Damage:3,tag:{SkullOwner:Slenderman,display:{Name:"Cabeza de slenderman"}},Count:1}],ArmorDropChances:[0F,0F,0F,2F],ActiveEffects:[{Id:5,Amplifier:0,Duration:2147483647},{Id:11,Amplifier:0,Duration:2147483647}]}