There is also a Flood elite in the first vehicle depot area, going right as you enter the room. It doesn't seem to move or attack... yet

On Jungle there is another Spartan (likely the same one from the elevator on Crow's Nest) watching over the final area from the left side of the rooftops. It seems to be invincible and disappears once you reach the bridge

If that spartan is on both jungle and base. it has to be on the highway somewhere yet to find it, if its there.

There also is a dead grunt in the barracks in crows nest with the words "Flipflap was here"

Originally posted by Dark Trooper Phase IV:

There also is a dead grunt in the barracks in crows nest with the words "Flipflap was here"

H O W DARE you say that FlipFlap was a grunt! he is FlipFlap!

Spotted the Nothing Is Real message on a pillar in the Crows Nest Barracks and my motion tracker showed a bunch of hostiles together after the hangar in the side room

When going through the motorpool on crowsnest (The area you travel through after leaving the barracks to go to the bomb in the base game) you can find infections form chilling in a room that is usually closed in the base game

On Tsavo, where you'd get the secret dialogue between two marines talking about the space elevator, you can find a destroyed warthog with a CE pistol on the ground

There doesn't seem to be any spartan on tsavo as of now, I've been looking around with both acrophobia and theater mode and aside from the CE magnum and the Wake Up signs there is not much going on in there