Aparoid crawlers
The Aparoids are vicious aliens that hail from an unknown, desolate planet in the Lylat System. They're capable of assimilating organic and mechanical lifeforms across the galaxy only to serve their malicious leader, the Aparoid Queen.
The Ultimate Story[]
The Aparoids were created by the Shadow Queen in an attempt to greatly widen the portal to the Shadow Realm. After Fox and his friends passed an elaborate exam brought together by their spirit counterparts, they revealed that they took part in a war that eventually lead to the Rifter shortly afterwards.
In the Secret Chronicles of Wolf O'Donnell, the Shadow Queen told Wolf that she had created these dark bugs in an attempt to carry out the Rifter. She then challenged him to try and stop them to which he did. Little did he know that it was a trick by the Shadow Queen to bring forth the Rifter.
The Aparoids contained essence of Dark magic within them and acted as receptacles to which if they were destroyed, that dark essence would be released and will immediately be used to widen the portal to the Shadow Realm. However, the dark essence needed to grow over time and if large enough, will be the spur that will bring forth the Rifter.
The Shadow Queen sent the bugs on a Cornerian frater 17 years prior to Starfox Assault. This was to test how much the Darkness within them grew. From there, she found that it was not large enough, so she decided to wait several more years.
WIthin the events of Starfox Assault, she decided that it was time to unleash the threat and sent out the bugs to attack the different planets of the Lylat System, provoking the Starfox team and the Cornerian army and even Star Wolf, including her own descendant of that realm, Wolf, to obliterate them. The Shadow Queen even took on the form of the Aparoid Queen as a means to overlook the invasion from within that dimension.
Shortly after the war ended, the portal to the Shadow Realm was large enough and the Shaman Emperor was finally released.