A cannon so large it double as a castle or maybe at least a tower... Reloads at just the touch of a button! Supports an engine of 8 TNT per shot and fires 2 TNT at once. I recommend only firing it 4 times before going back down and restocking the TNT as it can be difficult to get at the bottom rack. It still has enough room inside for a couple of extra racks of TNT to be added if necessary. Instructions on how to reload are in the video.

Update: The engine has been lengthened by one block so it now has a 12 TNT engine for a little bit more BOOOOM!