RedScreen

ON:/summon ArmorStand ~ ~ ~ {Equipment:[{},{},{},{},{id:skull,Count:1b,Damage:3s,tag:{SkullOwner:}}],HealF:0f,Small:1b,NoGravity:1b,Invisible:1b,DisabledSlots:31,Invulnerable:1b,Marker:1b,DeathTime:19s}

OFF:/summon ArmorStand ~ ~1 ~ {HealF:0f,Small:1b,NoGravity:1b,Invisible:1b,DisabledSlots:31,Invulnerable:1b,Marker:1b,DeathTime:19s}

Spawner:/summon FallingSand ~ ~1 ~ {Block:minecraft:mob_spawner,Time:1,Data:0,DropItem:0,TileEntityData:{EntityId:FallingSand,SpawnData:{Block:barrier},SpawnPotentials:[{Type:ArmorStand,Weight:1,Properties:{Equipment:[{},{},{},{},{id:skull,Count:1,Damage:3,tag:{SkullOwner:}}],HealF:0f,Small:1b,NoGravity:1b,Invisible:1b,DisabledSlots:31,Invulnerable:1b,Marker:1b,DeathTime:19s}},{Type:ArmorStand,Weight:1,Properties:{HealF:0f,Small:1b,NoGravity:1b,Invisible:1b,DisabledSlots:31,Invulnerable:1b,Marker:1b,DeathTime:19s}}],Delay:1s,SpawnCount:1s,MaxNearbyEntities:10s,RequiredPlayerRange:10s,SpawnRange:0s,MinSpawnDelay:0s,MaxSpawnDelay:0s}}