Tracking Name-Tag

This is a craftable item in the game that utilizes a nametag (which isn't craftable), and a lodestone block. Craft them together, and you get the Tracking Tag! This acts similar to a regular nametag, which you can use an anvil to name, and attach it to a mob, and the mob won't despawn. However, the player can use a compass on the tagged mob; just right-click, and the compass will point towards- aHem ... TRACK the mob. The Tracking Tag will be useful if you spawned the Wither, and it happened to float away across the world, eventually becoming unseen. The Tracking Tag would be used on the Wither to track it down, and kill it. Another example would be to use it on your horse. You get off to go check a village, but your horse is gone. Use the Tracking Tag to find your way back home. It would also be cool if the named Tracking Tag would show up on a map. Ta-Da!