Halo: Campaign Evolved Easter Eggs and Secrets

Halo: Campaign Evolved hides five easy-to-miss secrets across four campaign missions. Two of them are tucked into The Maw, while Megg requires a special setup on Legendary. If you are cleaning these up through Mission Select, read the trigger before loading the level. Megg is the only route here that needs a specific difficulty.

Megg: The Pillar of Autumn

Set the mission to Legendary. As soon as you enter the first room, climb onto the yellow container and stay there for about 15 seconds. Nothing obvious happens. That short wait is simply the first part of the trigger.

Continue through the mission until Captain Keyes gives you the pistol. Move into the next area, collect the ammunition and kill the three Grunts, then turn around and head back to the bridge. Kill Keyes with a headshot.

Three invincible Marines will now rush out of a room that was locked earlier. Do not try to fight them. Pull them toward the middle of the bridge, circle around them and sprint through the door they opened. Once you are inside the secret room, look up at the ceiling to find Megg and trigger the achievement.

Watch the Megg route on YouTube

Open the full The Pillar of Autumn mission guide.

Hidden music cue: Assault on the Control Room

Play until you leave an interior structure and step back outside. There are several enemies ahead and a Banshee close by. Run for the Banshee immediately. You may have to clear the nearby Elite before you can take off.

Look for the tall structure with three horizontal levels. Fly to the middle level and land with the nose of the Banshee pointing back toward the cliff and doorway you came from. Get out, walk to the outer edge and wait for the music to start. Reaching the correct spot also unlocks Madrigal Debut.

Watch the hidden music route on YouTube

Open the full Assault on the Control Room mission guide.

Captain Keyes' abandoned pipe: Keyes

This one is tiny, so slow down after you reach Keyes and finish the cutscene. Follow one of the tentacles extending from his body and inspect the end closely. A small pipe is hanging from it.

Keep the pipe in view for a few seconds. That is enough to unlock No Smoking. If nothing happens, adjust your aim until the pipe sits near the center of the screen and hold it there.

Watch the abandoned pipe location on YouTube

Open the full Keyes mission guide.

Thirsty Grunt: The Maw

The Thirsty Grunt can be found on any difficulty during the final Warthog run. After the bridge where Foehammer appears, keep driving into the tunnel. The road slopes down and bends slightly left. Watch the right wall during that turn and take the opening you see there.

Follow the narrow passage until another opening appears on the right. Park the Warthog, go through on foot and continue to the end. Listen to the Grunt at the back of the room to unlock Food Critic.

Watch the Thirsty Grunt route on YouTube

T-Rex: The Maw

T-Rex is also hidden in the Warthog escape, a little later than the Foehammer bridge. Continue toward the new docking bay until Cortana warns you about a large gap. Approach it at full speed, but aim slightly left so the Warthog lands on the small platform attached to the side.

Park beside the wall and use the Warthog as a step to reach the ledge above. Drop into the middle area and check the two small rooms. T-Rex is inside one of them, and finding it unlocks the T-Rex achievement.

Watch the T-Rex route on YouTube

Open the full The Maw mission guide.

Halo: Campaign Evolved Easter Eggs by Mission

For campaign collectibles, use the Skull locations and Terminal locations guides.

Last reviewed: July 24, 2026