Chicken Bomb - Minecraft PE

Build a tower. It doesn't matter what blocks you use, or the height, but make it pretty tall.

Break all the blocks except for the top one.

Spawn a ton of chickens on the floating block. They will all stay clumped up in a ball on the top. Be sure that you click on the corner of the block to spawn them, and don't click the chickens or else they will explode.

Break the block but be careful not to touch the chickens.

They will float down in a clump and when they hit the ground they'll explode.

You can also hit them or shoot them with a bow while they are on the block or floating down. Sadly this only works with chickens.

If you don't want a bunch of chickens lagging up your world, gather them up with seeds and then place some lava. They will all die.