Noisy, cricket-like insects that were found in marshy areas in the northerly regions of Middle-earth (e.g., Arthedain), Neekerbreekers (S."Thribrumath") were little more than a major nuisance. Their name was derived from their noisy, incessant night cry. Those experienced with and accustomed to travel in these regions soon learned to tolerate the sound of neekerbreekers, but travellers carrying dried grains, flour, or waybread were well advised to keep these supplies tightly wrapped in areas whereever the hideous "neek-breek, neek-breek!" could be heard, since neekerbreekers had been known to infest and devour such food.
Neekerbreekers were found in particularly foul swamps. Gigantic relatives of the cricket, these carnivores prefered solid meat. So, while it did not suck blood, a neekerbreeker would appropriate small chunks of a man's flesh. Any wound indicted by a Neekerbreeker had a chance of being infected with Yellow Rheum.