To get the Ghost, you must be start from the very beginning of the level and you must be playing on Legendary and on Co-op. The Ghost is a pretty fun vehicle to use on this level.
To get the Brute chopper, you must be playing at the Legendary difficulty and you must be doing co-op. Since the chopper can be a bit slow, you may want to boost right before you make a jump. Otherwise, you may fall a lot like I did in this video.
On the level The Covenent, if you hurry and use a mongoose, grab a ghost, and drive up the mountain, you will find the secret marine. The face of the marine may change sometimes. If you keep driving your ghost out, you will end up back to the middle of the level.
On the 343 Guilty Spark level, there are two random marines. One is kind of hidden while the other is insane and says a pretty cool message if you wait for him to say it.
This glitch is where you fly under a tight area like under a tank. Once you are underneath, change back to human and you will be instantly teleported to the last place you were standing as a human. This glitch can teleport you anywhere. It's pretty fun!
On the final level when you play it by yourself, if you don't like Arbiter and would prefer to do it yourself, you can. All you have to do is trap Arbiter behind a barrier. Watch the video for the full tutorial.
The final boss is very easy to beat. Just keep shooting his head with lasers until the sheild is down. Then neurohack him and keep shooting mortars at his head.
To do this trick, you must save Sgt. Johnson as you normally would. Before you enter the room where 343 Guilty Spark is waiting for you, kill Johnson and quickly run into that room. Kill the monitor as usual and Johnson should still be alive. Clear the flood and push Johnson to the Warthog and he will get in with you.
This is a video about 3 different glitches on the map Sandtrap in Halo 3. The first is a cloning/guardians glitch with the elephant. The second is a super jump glitch. The third is a glitch on how to protect yourself from the mines in the minefield.
On the level The Covenant, you already know about the time travel glitch to get out of the map. We have discovered a glitch to get a Hornet out of the map and into the future. You will need a power drain to capture a Hornet.
