Although seemingly replaced by the siliciferrous Dire Toms, the ancient Asshole Cells still persisted among the roots of the various flora which have since evolved, helping them acquire precious nitrogenous compounds to build these hosts up. Of course, there would spawn a few mutant lineages - Asshole Cells which, much like they have long ago, live independently from providing nutrients to flora; some of which were able to spread their mutations to floral mutualists. Eventually this would come to a point in which all remaining cultures of Asshole Cell would acquire these mutant genes, effectively replacing the ancestral stock and becoming a genetically distinct taxon - the Nitropellets.

Nitropellets function much like the Asshole Cell; all species can fix nitrogenous compounds into more useable forms (especially for flora which they often thrive in the roots of) or return nitrogen back into the atmosphere. The essential role of a nutrient recycler Nitropellets play in their ecosystems, combined with their ubiquity, make this taxon considered to be one “which must logically exist to maintain a biosphere”.

Nitropellets possess a distinct advantage over their cousins the Dire Toms in that they do not require silica in significant quantities to sustain themselves; because of this, Nitropellet species are much more versatile, capable of thriving in practically any environment.

Nitropellets are easily distinguished as they now have cilia.