TNT Barrel
For the explosive barrel in the Classic Trilogy, see Powder Keg.
TNT Barrels are explosive versions of Barrels. They have been around since the original Wonderland Adventures. When hit by Fireballs, they will explode and destroy anything adjacent to it. (This can make a chain reaction of explosions if there is a chain of TNT Barrels connected to each other.)
You can walk diagonally between any type of barrel.