Bat in a Bucket
Right-click a bat with an empty bucket to capture it (if you can!) and get the Bat in a Bucket. Right-click to release the captured bat, causing the outline of all entities around you to be visible for a moment.
Right-click on a banner or beacon while sneaking with a compass to bind the compass to the banner or beacon’s location.
If the target has been named on an anvil, the compass will use the target’s name. It will also color the compass name using the base color of the banner or the color of the glass above the beacon.
Use a bound compass on a crafting table to turn it back to a regular compass.