"The Megg" is one of the hardest easter eggs in Halo. After all once you see the Megg, its game over. Start a game on the Pillar of Autumn while on legendary difficulty. Jump on the cryo tube Master Chief comes out of. Jump on the shield recharger thing. Then, jump on the walkway. You'll see some barrels. Jump on the top one. Wait for that guy that woke you up to die, then jump down. Get to the captain and shoot him. As soon as Cortana says, 'rampant', find the door the invincible marines came out of. If you can get past them, another door will open. The Marines can't get you while you're in here. Look up at the 'M' made out of bullets. After you see it you're trapped and the marines now can kill you.