A cosmic entity, the Harrow existed for untold centuries feeding off galactic disasters. It was present at the trial of Galactus, possessing one of the audience. It hid aboard Galactus's Worldship (Taa II), in its cone of Psilence, realizing that the Eater of Worlds was the perfect host for itself. The Harrow kept its existence hidden with powerful psi-shields.
On the planet Orbucen, where Galactus began to harvest, the Harrow began possessing various people to cause more chaos. However, Richard Rider, the last Nova Centurion, assisting with the planetary evacuation, discovered the Harrow and began fighting it. Rider managed to expose the parasite to Galactus by disrupting its psi-shield. Galactus then incinerated the Harrow.
- Insect Form: Harrow resembles a humanoid insect.
- Telepathy: The Harrow is a powerful enough telepath that it can exist as a psionic entity. The closer a being is to The Harrow's true body, the more powerful its telepathy is, at point blank range the psychic defenses of a Nova Corps helmet can't protect an individual from it.
- Telepathic Possession: Harrow is capable of possessing individuals and controlling their actions. The possession causes a bleeding around the eyes and eventually causes the individual's death. 
- Cone of Psilence: The Harrow can protect itself from detection by powerful beings such as Galactus and his Heralds within its 'Cone of Psilence'.
- Biological Manipulation:: Harrow can also reshape their bodies to an unknown degree.
- Psychic Shielding: The Harrow requires a body with which to wreak havoc through, psychic shielding of sufficient strength can stop it from being able to possess a body.
- Capture: If the body The Harrow resides within is trapped within a powerful enough barrier then The Harrow will become trapped within it, though it can eventually adapt and escape.
- 3 appearance(s) of Harrow (Earth-616)
- 1 appearance(s) in handbook(s) of Harrow (Earth-616)
- 2 image(s) of Harrow (Earth-616)