Epidemius
Epidemius is the greatest of the Plaguebearers and Nurgle's favourite little tallyman. This little fucker is in charge of searching for disease, bacteria, and more of... them..., as well as noting the potency of Nurgle's new plagues, and coming up with new interesting new symptoms for Nurgle's new plagues. He is also a lazy fuck, just like his patron, and literally has his own moving squad of Nurglings that carry him around. Even as Epidemius surveys and takes notes of the spread of filth and decay, Nurgle knows this, and starts working on some more nasty shit. Because of this, Epidemius focuses on his task even if he takes a power fist to the face, cuz say he were to make an error or untimely observation, Nurgle would probably start using him as the squeegee for his plague cauldron. He's even uglier than a normal Plaguebearer, and the nurglings that carry him also secrete oil that he uses to write with (on pages made of their discarded skin). Lovely.
Warhammer Fantasy
"MOM! GET THE PAINTER!!!! MOMMYY!!! MOMM!!!! MOM!!!"
- – One of the Altdorf cannon engineer who "accidently" shot Epidemius after rotating his cannon 360 degrees.
He is known as the "Maggot King" and he is Nurgle’s chosen Tallyman, one of the seven Proctors of Pestilence and the cataloguer of all the Plaguelord's diseases. In the end time, he got YOLO NO SCOP'ED by a cannon ball during the battle of Altdorf. Must've be a pretty easy target for a fat lazy couch potato.
Horus Heresy
He was summoned on Calth during the Horus Heresy, and probably banished by the Ultramarines, or Roboute Guilliman