Avery (first name unkown) attended Hogwarts School of Witchcraft and Wizardry at the same time as Severus Snape, Lily Potter (then Evans), James Potter, Sirius Black, Peter Pettigrew, Remus Lupin, and others. Sorted into Slytherin House, Avery, along with his cohort Mulciber, displayed a marked penchant for cruelty, which continued after finishing Hogwarts - both became Death Eaters.
Though he fought for Voldemort in the First Wizarding War, Avery was among those who evaded Azkaban but did not attempt to find their master after his downfall. He did, however, return immediately upon Voldemort's summoning in the graveyard following his resurrection. Avery begged forgiveness and was subjected to the Cruciatus Curse by Voldemort, who refused to forgive anyone. Avery remained loyal and was among the group of Death Eaters who fought for the prophecy at the Department of Mysteries. Following his subsequent imprisonment, Avery escaped, and may have fought at the Battle of Hogwarts. Whether or not he fought, it is not known whether he survives.