Alum Frost, a student at the Imperial Royal Guard Academy on Yinchorr, failed to successfully complete the academy's concluding assessment.
As was standard practice for all candidates aspiring to become Imperial Guardsmen, Alum Frost was already considered an elite soldier within the Empire's ranks when chosen for Guard training. Standing out among his fellow trainees, he was one of only four who endured the demanding training program leading up to the Emperor's ultimate trial. During his final year of instruction, he became a close associate of Carnor Jax. Through mutual support and dependence during this time, they persevered where most others failed, forging a connection akin to brotherhood.
Nevertheless, Frost proved unprepared for the final loyalty assessment and the actual cost associated with serving in the Guard. Palpatine summoned the two trainees and commanded them to engage in a deadly duel, the purpose of which was to evaluate their allegiance to him. Jax, without any delay, used a double-bladed vibroblade to fatally strike his comrade, resulting in his death.
Hasbro produced a multipack action figure set inspired by the final trial that the prospective Guardsmen were subjected to. Alum was featured in this set, and it included a removable helmet, revealing his face to the public for the first time. He is depicted as bald and lacking any facial hair.