Megg
From Halopedia, the Halo wiki
Jaime Griesemer, lead designer of Halo: Combat Evolved, gave his girlfriend Meg (aka Pallor of Subnova) a gift in the form of an easter egg. The egg, affectionately called the Megg, was hidden in Pillar of Autumn (Level) under a series of almost impossible feats to ensure that no one could find it accidentally. The Megg itself is a heart made from human blood, with an "M" made of bullet holes in the center.
To see this easter egg, follow the directions below carefully.
- Start the level on single player mode, legendary difficulty.
- After awakening from the cryotube, walk toward the canisters behind you (opposite the exit).
- Crouch jump on top the yellow canister and then jump back down and move through the level as normal, (skip the Marine who gets in your way) until you get to the bridge.
- Once there trigger the cinematic by walking over to Captain Keyes.
- After you get the pistol, go through the exit (kill the Grunts) and get the assault rifle, then go back to the bridge.
- Kill Keyes or/and whack the crewmen (not sitting down), which will send in the "Invincible Marines" out of a previously locked door, (the right side of the exit).
- As Cortana finishes saying, "The Master Chief has gone Rampant," a second door (right behind the first locked door) unlocks.
- Move to the other side of the bridge with the locked door and use the assault rifle to keep the Marines at bay. Then skip past through the corridor and head in the second door. (The second door will still be locked, if you go to it right when the Marines come out. Kill Keyes, stay at that position, awaiting the marines to "crowd" one side of the bridge. Then zoom past the "empty" side blazing lead, and into the door way.)
- Enter the hallway, at the end you will find the Megg on the ceiling. (Use your flashlight)
- Get killed or spend all your bullets on the marines (stay in your room for cover). You get a bloodied hall. You have to die sometime.
Halo 2
There is also a Megg egg located in Halo 2. Discovered by de-compiling the game script by "Soldier of Light" from High Impact Halo, Halo 2's version turned out to be much less complicated. It is activated by going through the first level, Cairo Station, on Legendary, without losing your shields once. Upon reaching the final bomb room, a sound clip will play. The text of the clip is: "Megg, please report to the red courtesy phone. Megg, to the red courtesy phone."
Halo 3
There is a Megg symbol in the multiplayer map Ghost Town. At the front of the map by the large blocked-off tunnel turn right to the tree that connects to the first major piece of concrete. Between two branches there will be the third Megg.