[One Command, 1.12] TNT Block

How to use:

Rename a bat spawn egg to "TntBlock".
Spawn the bat on top of any block.
When you break that block, it will become primed tnt.


/summon falling_block ~ ~1 ~ {Block:repeating_command_block,Time:1,TileEntityData:{auto:1b,Command:"/execute @e[type=bat,name=TntBlock] ~ ~ ~ /summon bat ~ ~-1 ~ {CustomName:tntblock,Invulnerable:1,NoAI:1,Silent:1,Age:-1000,NoGravity:1}"},Passengers:[{id:"falling_block",Block:"repeating_command_block",Time:1,TileEntityData:{auto:1b,Command:"/execute @e[type=bat,name=tntblock] ~ ~ ~ /kill @e[type=bat,name=TntBlock,r=1]"},Passengers:[{id:"falling_block",Block:"repeating_command_block",Time:1,TileEntityData:{auto:1b,Command:"/execute @e[type=bat,name=tntblock] ~ ~ ~ detect ~ ~ ~ air 0 /summon tnt ~ ~ ~ {Fuse:40}"},Passengers:[{id:"falling_block",Block:"repeating_command_block",Time:1,TileEntityData:{auto:1b,Command:"/execute @e[type=tnt] ~ ~ ~ /kill @e[type=bat,name=tntblock]"}}]}]}]}