Anvil

An Anvil is an upcoming block that is expected to be in 1.4. It will be used for the new item repair interface. When placed above air it will fall. It will also inflict damage when dropped on players or mobs. Damage amount depends on fall altitude. Anvil-related death message is "Player was squashed by a falling anvil". If it lands on a transparent block (like torches, rails, etc.), it will destroy that item instead of dropping itself as an item like sand and gravel do. It will sink to the bottom of water and lava. When dropped on a Pressure Plate, a Boat, or Spider Webs, the Anvil will drop as an item.

A dispenser will dispense the dropped anvil item.

Anvils can be mined with a pickaxe, but they are immune to TNT.

The file where the values are found in are in the ala.class on the root folder of the .jar archive.

All anvil blocks have the same block id, only the damage of the item block are different from the three types.

The damage you receive from being hit by a falling anvil:

Anvil Damage = (Fallen blocks - 2) * 1.5

With the same blast resistance of obsidian and the same hardness of a ore storage block with 0.5F, making this anvil block blast proof. This block might have some redstone uses for blast resistant propitiates.

This is the anvil part public static final ala cj = new ahj(145).c(5.0F).b(2000.0F).b("anvil").r;

Obsidian for comparing public static final ala ar = new aju(49, 37).c(50.0F).b(2000.0F).a(h).b("obsidian");

Trivia

 * It takes a total of 55 iron ingots to craft an anvil
 * The anvil is a common item found in many classic comics and cartoons, the ability to hurt an entity on impact is a perfect example of this, however it may be simply because an anvil is actually really heavy, depending on it's size.