The Ptolemaic Army are the main antagonists of Metal Slug 5. They are an armed guerrilla force made up of mercenaries and special agents, having a full arsenal of weaponry and sophisticated machines under their disposal, which includes an assortment of combat mechas. However, the Ptolemaic Army is founded and commanded by the members of a mysterious cult of masked shamans called the "Ptolemaics" at the core of the Army, who worship an ancient demon known as the Avatar of Evil, and seek to achieve world domination by bringing this demon back into our world.
To help further this goal, their agents infiltrated the Regular Army headquarters and stole a disk containing data about the latest generation Metal Slugs, as well as many other vehicles used by the Regular Army and the Rebel Army. Using this data, they created their own variations of the Metal Slug, which included a gigantic sized Metal Slug and the Black Hound, which was an enhanced Metal Slug in all aspects.
Treating the incident with utmost urgency, Regular Army HQ orders the P.F. Squad and S.P.A.R.R.O.W.S. soldiers to follow the tracks of the Ptolemaic Army and stop whatever plan they have in mind.
The conflict ended with the demon being defeated. However, it flew away before its true identity could be revealed. The Ptolemaic threat seemed to be at an end.
The Ptolemaic Soldiers are a militant arm of the Ptolemaic Army. Lethally skilled and dangerous, Ptolemaic soldiers within the infantry are seen as a "Special forces" unit. Not only their weapons are more advanced than those used by the Rebel Army, Soldiers shoot and toss grenades at players with much better accuracy and draw knives at much faster rate than Rebel Army grunts: players engage them at close combat at players' own risks.
Ptolemaic Soldiers consist of:
- Officers - they lead Ptolemaic soldiers. They shoot with handguns and have very high physical staminas and durabilities.
- Guerrillas - they come with various weapons (machine gunners, bazookamen, mortar, mine layers, mechanized units etc.)
- Masked Commandos - Highly skilled at close combat, jump attack and knife-throwing.
- Snipers - shoot their victims from range using concealment. Has little to no hand-to-hand combat skills.
The Ptolemaic Shamans are the leaders of the Ptolemaic Army, possessing numerous supernatural abilities. They were apparently formed when a Native picked up a white mask and put it on, causing him to be struck by lightning. Their goal is to summon the Evil Spirit Incarnate to our world.
- Black Shamans - Black Shamans are the lowest ranked shamans, serving as soldiers. They are seen stationed at an underwater facility in Mission 4, before retreating.
- Red Shamans - Higher ranked shamans who serve as officers. A red shaman appears several times throughout the game, fleeing when the player comes near before eventually confronting the player in stage 5.
- Purple Shamans - Shamans ranked higher than red ones. They are seen stationed in the city before fighting the player in the tower.
- Green Shamans - The highest ranked shamans who appear only in the tower.
- Ptolemaios - An unused boss who was apparently the Native who got struck by lightning in the first level. He pilots a giant flying tower, and was originally intended to be the final boss of the game before being replaced by Evil Spirit Incarnate.
- Metal Rear
- Shooting Ray
- Wall Crawler
- Black Hound
- The Ptolemaic Army's original name came from the adjective formed from the name of Greco-Egyptian 2nd-century AD geographer and astronomer/astrologer Claudius Ptolemy. That name also became part of Ptolemy I Soter of the Ptolemaic Dynasty which founded and ruled the Ptolemaic Kingdom in 305 BC, of the citadel known as the Ptolemaic Baris (also known as Ptolemaic Acra), and of the Ptolemaic system.
- They appear to be based on the Brotherhood of Nod from the Command and Conquer series due to their combat styles, as well as real life Illuminati/Freemasonry secret societies given their pseudo-religious nature.
- If the Ptolemaic Boss is their leader, then the Plotemaic army could be the native enchance the intelligents because of the mask they wear, but in the battle, he does not have a mask, that gives that they may summon the Evil Spirit Incarnate to the world as their great demonic leader. But if it is their leader, then the Ptolemaic Boss may have turned into a demon in the final battle wanting to end the characters' disturbances into their success.
- They have original ideas but instead steals ideas from the S.P.A.R.R.O.W.S, the Regular Army and the Rebel Army the enchancing to make a bit different and more powerful.
- All shamans have the same attack and health, they only have hood colors to show their ranks.
- In the revised version of Metal Slug 5, the Guerrillas and Special Forces have a color variant.
- The only Ptolemaic army who are not evil but allies with a Regular Army are those who are loyal to their commanders such as Dragunov and Caroline which is only seen in Metal Slug Attack especially during United Front, an extra ops event where the Regular Army are allies with other armies besides the Rebel Army (The event's main antagonist).