Minecraft wiki entry for Command_blocks_and_functions, associated text: /setblock ~2 ~1 ~2 spawner{SpawnData:{id:skeleton_horse,Tame:1,Passengers:[{id:skeleton,HandItems:[{id:bow,Count:1,tag:{Enchantments:[{id:flame,lvl:1}]}}],ArmorItems:[{},{},{},{id:player_head,Count:1,tag:{Enchantments:[{id:protection,lvl:2}],SkullOwner:MHF_Spider}}]}]}} replace