The Excavator is a giant mining machine. They appear in the campaign mission "Vorkuta", the multiplayer map Radiation, and the Zombies level Moon. On the former two and in Call of Duty: Modern Warfare 2, they appear only in the background. In Call of Duty: Modern Warfare 3, one appears in the mission "Down the Rabbit Hole" and the Special Ops mission "Black Ice".
Three excavators appear in Moon, each with their own control panel in the starting room. When not active, they sit on the edges of the map. When an Excavator activates, the players will be given five warnings - one each at 4, 3, and 2 minutes, one 60 seconds before, and another 30 seconds before it begins to breach. The Excavator will slowly move toward the area it breaches. They will have to be deactivated by using the Hacker on the respective control panel. These panels are found in the starting room. If the players let it continue, the Excavator begins drilling into the base, blocking off one of the doors and making it harder to navigate. The Excavator will keep going until the end of the game unless the panel controlling it is hacked. When the Excavator breaches an area, there will no longer be any oxygen or normal gravity. Instead, there will be low gravity there and no oxygen. The Excavator must be allowed to breach Tunnel 6 for Richtofen's Grand Scheme.
Usually the first Excavator activates around round 6-7, although it can be activated as early as the power has been turned on. Other Excavators activate randomly after that.
The following excavators dig into the following areas on the map, seemingly randomly throughout the game:
- Pi (breaches Tunnel 6): In the room blocking off the last door into air lock and when it has breached, it makes buying the M16 and its ammo impossible.
- Omicron (breaches Tunnel 11): In first room blocking off the second door and when it has breached, it makes buying the PM63 and its ammo impossible.
- Epsilon (breaches the Biodome): It breaches the ceiling of the Biodome and causes major decompression, which makes it so falling off of a Gravity Lift does not cause damage. It does not block anything when breached.
Of the three excavator terminals in the spawn room, only Omicron is on the left side. Pi and Epsilon are together on the right side of the spawn room. All three terminals are very close to doors, making them easier to hack without oxygen in the spawn room.
One Giant Leap (5 / Bronze Trophy ) - In Moon, become trapped in the Receiving Area and free yourself through resurrection in co-op. (Requires Excavators Pi and Omicron to be blocking off the Receiving/Starting Area from the rest of the map.)
Ground Control (10 / Bronze Trophy ) - In Moon, prevent each excavator from breaching the base in one game.
- Excavators will kill the player if they run into the blade as the excavator comes down. They will not be able to be revived and will respawn next round.
- The stands the control panels are on have symbols for each excavator, an E, O, and a Pi symbol. The E was mistakenly placed on the stand for Omicron, and the O was misplaced on Epsilon's.
- Walking into an Excavator blade will down the player in one hit (or three with Juggernog).