(The fact there's a multiple characters option for gender but NOT for the species part is troublesome.)

Redraw of both variants of plagueling
https://www.furaffinity.net/view/53601986/
https://www.furaffinity.net/view/53602048/

Plaguelings are offspring of Aratrice, just like the followers there is a rat and a crow variant.

PLAGUE RATS: inhabit the plague realm, and can be summoned from the plague realm by followers, plague rats will have a divine disease that can help aid in combat, much like followers do, they can be found either scampering about in the wilds, or covered in sacks and satchels, used to transport, these rats are about the size of dogs, and can get even bigger in some cases, you could say they're rodents of unusual size...

PLAGUE CROWS: They can be seen flying around in the sky within the plague realm, and also help keep the plague realm floating above the infinite sea of bacteria, as Aratrice's worship grows and there's more member of the plagalatry, they are able to create more plaguelings, when there are enough new crow types they will dive down in groups into the sea to lift up a new chunk of land, expanding the realm, and holding it up, they take turns in rotation holding it up with other crows, they don't have to do that forever.

These too can be summoned in combat, but will actually inflict diseases on enemies, opposed to just having a self beneficial one like the plague rats and the followers do.