Exo-Parasites are a race of parasitic alien beings that hail from Exo-Space, the negative space between realities. Along with Shoggoths and Viral Parallels, they are the scavengers of the Outer Omniverse, and voracious species that cross between realities and consume their inhabitants.

Ms. America fought a group of those "locals" of the Exo-Space, possibly including Exo-Parasites, when she entered Exo-Space in order to close a rift in space and time.^[1]

The Exo-Parasites found their way to the universe of Earth-2099 where they fought the Nova Corps. Getting a taste of the Corps' Nova Force, the Exo-Parasites began hunting down each member of the Nova Corps to feed on their power. The Exo-Parasites attacked Xandar, destroying almost all of the Corps' forces. This left only a few surviving Novas, such as Wolverine, who was infused with the Nova Force and managed to fight back against the monsters.^[2]

• The Exo-Parasites are seemingly inspired by the Cthulhu Mythos, described as similar to the Shoggoths (with whom they share their location and goals in the Exo-Space),^[1] and being seemingly referenced (along other creatures) as "eldritch forms and predatory concepts", and (individually) as "a Cthulhu".^[3]