TNT

TNT is a block currently only available in Survival. It behaves like the Creeper's explosion. Upon being struck by the player, it will start smoking and beeping white. If there are no blocks to hold up the TNT block, activating it will make it affected by gravity and it will fall. After a few seconds, it explodes, destroying a vast amount of blocks, mobs that are nearby, and even the player if he is not careful.

TNT may or may not be added to the next Creative mode update. It is a major source of griefing, and has been known to break the game. However, it is possible it could be only be placed by admins, as it is very useful for digging out holes.