A member of the Elucidated Brethren of the Ebon Night, named for his day-job like Brother Dunnikin. Possibly because he lacked the imagination to call himself anything else: at meetings of the Brethren in Guards! Guards!, his comments suggest he was only slightly less thick than the plaster he'd worked with.
Believed himself horribly oppressed by his landlord, who kept demanding back rent he fervently denied owing. His neighbors' complaints about the noises from his flat all night long likewise struck him as totally oppressive, because a man needs some time in which to learn to play the tuba.
Brother Plasterer was extremely pleased by the successful summoning of the great Ankh-Morpork dragon, considering it a blow for justice in a world of unfairness. How he felt about being incinerated himself, not long after, is unrecorded.