This is a small command block setup to troll your friends who are looking for diamond. The troll block looks like a diamond block, but will get up and run away when approached - then settle down and become a block again when far enough away.

To use, paste schematic into your world. It's a good idea to place the command blocks in your spawn chunks (around your world spawn), so they will be running at all time. Replace the redstone block at the edge of the device, then run this command:

/scoreboard objectives add Troll dummy

Now, use the following command to summon troll blocks wherever you want them:

/summon ArmorStand ~ ~ ~ {CustomName:Troll}

A troll block will be summoned at your feet, and will run away.

The installation is a bit clunky - mostly because this is kind of a funny thing rather than actually useful :) Let me know if you have problems getting it to work and I could streamline it a bit more.