The Nexosporidium are aliens that serve as antagonists in Path of the Furon and take the place of Majestic and KGB as the fourth alert level enemies. They first appear in Las Paradiso, where they attempt to destroy Crypto and Pox, they are later seen at the Sunnywood stadium. Their technology is later encountered in Shen Long, and their source is located in Belleville. And finally, they are spotted on Gorta, where the final confrontation takes place.
There is three type of Nexos, each appearing at different events, and different places.
Nexosporidium Warrior - Alien cyborgs that were thought to be extinct years ago. Basic Nexos Infantry, there are three different types, red the strongest, blue the weakest, and green the common foot soldiers. They are armed with a powerful phase cannon in their right arm, and use a small energy flail in close combat; they can also fire rockets at their enemies. The Red Nexos are the largest of the three and are located around the Fourth Ring of Furon, acting as law enforcement. Green and Blue Nexos are encountered during missions and when the alert level is red.
Nexosporidium Saucers - These are Saucers piloted by Nexos warriors, and are armed with twin energy cannons, that resemble Crypto's plasma cannons to some degree. They serve as the Nexo's air force and will only attack while Crypto is piloting his Saucer. They once destroyed a human Military battalion in a battle for a lost relic.
Nexosporidium Warriors are a race of cyborgs that were once thought to be extinct. Used as an army by the conspirators on the Furon Homeworld. Emperor Meningitis had them re-cloned for his serve as his own body guards. They serve as the main enemy for Destroy All Humans! Path of the Furon, and serve as a replacement for the Blisk from Destroy All Humans! 2.
- Sporidium may be a run on word on Crypto's full name Cryptosporidium. At one point Crypto even makes the statement: " Nexosporidium vs. Cryptosporidium".