Disappearing Truth

The Disappearing Truth is a glitch that can be performed on Halo 3 campaign level The Covenant.

How To Do It
In the last section of the level The Covenant, after you have reached and killed the Prophet of Truth, you can melee or teabag the Prophet of Truth a couple of times, causing him to fall through the platform on which his body rests. When he falls beneath the platform you can see him, but sadly you cannot reach him.

This also works on the Flood Combat Forms if you manage to kill them on the platform without destroying the body.