What is a group of Altarboys called?

A group of altarboys is commonly called a Fidget.

A collective noun for altarboys is a "chorus". A chorus of altarboys refers to a group or ensemble typically consisting of young boys serving and assisting in religious ceremonies, particularly in Christian church settings. These young individuals diligently carry out various tasks such as lighting candles, assisting the clergy, handling ceremonial objects, and performing other duties to support seamless religious services. Whether it is during Holy Mass, sacraments, or other important religious events, the chorus of altarboys plays an important role in enhancing the atmosphere of devotion and piety. Their synchronization and cooperation further contribute to the overall smooth flow of the liturgy, creating a sense of reverence and unity among the congregation.