This video shows you how to get out of “The Covenant” campaign level on Halo 3.
Here’s how to get an invisible warthog in Halo 3.
This video shows you how to get out of Isolation and run around the top of the map.
With the Grunt Birthday Party Skull, every time you shoot a grunt in the head he will explode with confetti and you will hear children cheering.
Here’s how to get a flying elephant on Sandtrap.
(No there’s really no elephant in Halo 3)
Learn how to get out of High Ground on Halo 3. (You must be in Forge mode to do this though 
)
You can find a guy in his underwear with his hands behind his head in Halo 3’s campaign.
This video shows how to unlock the song “Siege of Madrigal” which was in the old Myth game also.
This video shows how to get the hardest skull in Halo 3 - the “I Would Have Been Your Daddy” skull, aka IWHBYD skull.
How to get into a secret room on Last Resort.