Oh, crap...
The Snowtomic bomb is when you put snow in a hydrogen bomb. Somehow, this makes it more powerful, and gives it the ability to freeze targets in a nuclear winter. It was first invented by the (semi) powerful Ducky Empire, even though all they did was ripped off the bombs from United States of UnAmerica and Soviet Russia. This bomb was deployed quite often in The Old War.
The average snowtomic bomb weighs about 7 tons, most of which is metal and snow. There is little actual TNT in it, only 500 kilograms. (We're too lazy to convert into imperial, so we're just going to say there's also 500 pounds of TNT. That's the same thing, right?) The secret of the snowtomic bomb is heavily guarded, just in case Somebody actually cares enough to try to figure it out.
There are some negative side effects involving the use of the snowtomic bomb. First, launching it into the air creates a sheet of ice. This ice is actually just frozen water, but Ducky doesn't know that. Then, most of the snow from the bomb drops on any place it flies over. The snow is radioactive, so The Cat in the Hat wonders why there is green snow, but figures it can't be as bad as yellow snow. Finally, when it detonates, it blows up.
When the bomb goes off, everything within a 75 camel radius is instantly frozen and Everybody is turned into a snowman. Anything within a 700 camel radius is trapped in an eternal winter which lasts for about three years, during which time Evil Snowmen run around unopposed as Everybody is frozen. But then they just send bombs back at the Ducky Empire, and everyone blows up, and Earth is uninhabited, happily ever after.
Also, the Snowtomic bomb is why Greenland is covered in ice and snow instead of Iceland...