The Monoeyes are a 15 meters tall humanoid alien and the enigmatic guardians of The Ten Commandments of Moses. So named for the large eye that seems to be their sole facial feature. They will attack anyone who dares to get too close to the beacon.
Once you reach the end of the stage, the searchlights on the site will burst, and then six (or eight on hard mode) Monoeyes will materialize around the beacon. They will then levitate around it while firing energy bolts aimed at the player, in fixed intervals, depending on the speed that they are rotating. The ideal way to get rid of them is by turning into a zombie before reaching them, and, as the battle starts, uses a blood vomit right away. This will finish off up to four of the eight monoeyes (on hard mode, they are more packed together). After this it is advisable to revert back to human form with a first aid box (best done by killing a doctor zombie before the battle begins, without taking the first aid box, then using the blood vomit before reverting to a human) and finish them off using the regular grenades.
Dark Monoeye - is a presumably subspecies of Monoeyes found only in Metal Slug Attack. It is similar to the regular ones, but however it doesn't spin around the enemy in an invulnerable state, instead it does summon Monoliths similar to The Ten Commandments of Moses attack.
- Monoeyes are the one subspecies of the Martians that have a physiology closest to that of the humans.
- Like most members of the Martian forces, Monoeye abilities appear to be mental in nature. In the Monoeyes case, they appear to posses teleportation, telekinesis and pyrokinesis
- There are enemies in the Kid Icarus series called Monoeyes that resemble flying pink balls with a single eye and three or more tentacles.
|Human||Rebel Infantry | Arabian Infantry | Samurai Infantry | Pirates | Scientists | Ptolemaic Infantry | Natives | Hunters | Future Rebels|
|Undead||Mummies (Mummy Generator) | Dog Mummy | Mutated Soldiers | Zombies | Tar Man | Clones|
|Mutant||Bat | Chowmein-Conga | Ohumein-Conga | Enormous Moray | Jellyfish | Flying Killer | Man Eater | Huge Locust | Sasquatch | Maggot | Big Snail | Giant Caterpillar | Squid | Huge Ivy|
|Alien||Monoeye | Ring Laser Mecha | Hopper Mecha | Mars Mecha | Mars People | Big Eye | UFO | Mini-UFO | Invader Squad | Winged Invader | Flying Parasite | Hunter Walker | Hunter Lord | Scavenger | Crab-Tank | Vanguard | Smasher | Invader UFO | Indestructible UFO | Flying Core|