Harder Mobs 1.12

summon falling_block ~ ~1 ~ {Block:stone,Time:1,Passengers:[{id:falling_block,Block:redstone_block,Time:1,Passengers:[{id:falling_block,Block:activator_rail,Time:1,Passengers:[{id:commandblock_minecart,Command:gamerule commandBlockOutput false},{id:commandblock_minecart,Command:fill ~3 ~-2 ~ ~20 ~-2 ~ chain_command_block 5},{id:commandblock_minecart,Command:setblock ~8 ~-2 ~ repeating_command_block 13},{id:commandblock_minecart,Command:setblock ~5 ~-2 ~ repeating_command_block 5},{id:commandblock_minecart,Command:setblock ~3 ~-2 ~ command_block 5},{id:commandblock_minecart,Command:blockdata ~20 ~-2 ~ {auto:1,Command:	/execute @e[type=husk] ~ ~ ~ /effect @p[r=4] nausea 5 1}},{id:commandblock_minecart,Command:blockdata ~19 ~-2 ~ {auto:1,Command:	/execute @e[type=witch] ~ ~ ~ /effect @e[type=zombie,r=5] resistance 5 5}},{id:commandblock_minecart,Command:blockdata ~18 ~-2 ~ {auto:1,Command:	/execute @e[type=magma_cube] ~ ~ ~ /fill ~ ~ ~ ~ ~ ~ fire 0 keep}},{id:commandblock_minecart,Command:blockdata ~17 ~-2 ~ {auto:1,Command:	/execute @e[type=cave_spider] ~ ~ ~ /effect @p[r=5] slowness 5 5}},{id:commandblock_minecart,Command:blockdata ~16 ~-2 ~ {auto:1,Command:	/execute @e[type=stray] ~ ~ ~ /effect @p[r=5] mining_fatigue 25 1}},{id:commandblock_minecart,Command:blockdata ~15 ~-2 ~ {auto:1,Command:	/execute @e[type=skeleton] ~ ~ ~ /fill ~1 ~ ~1 ~ ~ ~ air 0 replace torch}},{id:commandblock_minecart,Command:blockdata ~14 ~-2 ~ {auto:1,Command:	/execute @e[type=endermite] ~ ~ ~ /spreadplayers ~ ~ 1 4 @p[r=3]}},{id:commandblock_minecart,Command:blockdata ~13 ~-2 ~ {auto:1,Command:	/execute @e[type=spider] ~ ~ ~ /execute @a[r=3] ~ ~ ~ /setblock ~ ~ ~ web 0 keep}},{id:commandblock_minecart,Command:blockdata ~12 ~-2 ~ {auto:1,Command:	/execute @e[type=enderman] ~ ~ ~ /effect @a[r=5] blindness 4 4}},{id:commandblock_minecart,Command:blockdata ~11 ~-2 ~ {auto:1,Command:	/execute @e[type=creeper] ~ ~ ~ /effect @a[r=5] poison 2 2}},{id:commandblock_minecart,Command:blockdata ~10 ~-2 ~ {auto:1,Command:	/effect @e[type=spider] jump_boost 2 1}},{id:commandblock_minecart,Command:blockdata ~9 ~-2 ~ {auto:1,Command:	/execute @e[type=zombie] ~ ~ ~ /fill ~-1 ~ ~-1 ~1 ~1 ~1 air 0 destroy}},{id:commandblock_minecart,Command:blockdata ~8 ~-2 ~ {auto:1,Command: /scoreboard players set timer timer 0}},{id:commandblock_minecart,Command:blockdata ~7 ~-2 ~ {auto:1,Command:	/scoreboard players test timer timer 100}},{id:commandblock_minecart,Command:blockdata ~6 ~-2 ~ {auto:1,Command:	/scoreboard players add timer timer 1}},{id:commandblock_minecart,Command:blockdata ~5 ~-2 ~ {auto:1,Command: !!! Timer !!!}},{id:commandblock_minecart,Command:blockdata ~4 ~-2 ~ {auto:1,Command:/gamerule logAdminCommands false}},{id:commandblock_minecart,Command:blockdata ~3 ~-2 ~ {auto:1,Command: /scoreboard objectives add timer dummy}},{id:commandblock_minecart,Command:setblock ~ ~ ~1 command_block 0 0 {Command:fill ~ ~-3 ~-1 ~ ~ ~ air}},{id:commandblock_minecart,Command:setblock ~ ~-1 ~1 redstone_block},{id:commandblock_minecart,Command:kill @e[type=commandblock_minecart,r=1]}]}]}]}