Farnum is the proprietor and master of ceremonies of the Rumbledome, a large-scale arena located in Crown City that hosts monster truck rallies and robotic combat exhibitions. He is a human character whose primary professional role involves not only hosting these events but also scouting and hiring the talent that performs within the venue.

In terms of personality, Farnum comes across as a seasoned and opportunistic showman. He is focused on putting on a good show for the audience and is willing to adapt on the fly when unexpected situations arise. When the Decepticon Groundpounder unexpectedly arrives at the Rumbledome and demands a fight, Farnum does not panic or call for help. Instead, he chooses to play along, recognizing the potential for an exciting spectacle and immediately ordering one of his contracted fighters to battle the newcomer. This decision highlights a pragmatic and somewhat opportunistic streak, prioritizing the success of the event over standard security concerns. He is also presented as a professional who is difficult to impress; when Denny and Russell Clay first demonstrate their robotic rig Dino-Bash, Farnum is notably unimpressed by the initial showing. However, his professional eye for talent is evident when he later mistakes the Decepticon Headlock for part of a remote-controlled robot act and promptly offers the pair a permanent slot at the arena.

Farnum's role in the story is primarily that of a supporting human character who facilitates a key encounter in the episode The Champ. He serves as the catalyst for the arena battle between the Autobot Dinobot Grimlock and the Decepticon Groundpounder. Throughout this event, Farnum observes the match from a private box high above the stadium floor, acting as an in-universe commentator and coordinator. His functional role in the plot is to provide a logical setting and reason for the two powerful robots to engage in a contained, gladiatorial-style confrontation. He has direct professional interactions with Denny and Russell Clay when they attempt to enter Dino-Bash into the competition, and his inaction or active encouragement allows the Decepticons Groundpounder and Headlock to participate in and disrupt the event.

Regarding his relationships, the most significant are professional in nature. He interacts directly with Denny Clay as a talent scout and venue owner, and with the Decepticons Groundpounder and Headlock, whom he initially mistakes for a legitimate fighting act. There is no information available about his personal relationships or family connections.

Farnum does not undergo a significant character arc or personal development within the narrative. His role is confined to a single episode, and his primary purpose is to serve as a functional fixture of the Rumbledome. The major event of the episode, the collapse of the arena due to the stress of the battle, forces him to flee from his observation box, but this does not lead to any recorded change in his personality or future behavior.

As for notable abilities, Farnum possesses no superhuman or combat-oriented skills. His abilities are entirely related to his profession and include effective crowd control and event management as the MC, the ability to scout and evaluate talent for a combat arena, and the quick thinking to adapt his show in the face of unexpected developments, such as the sudden arrival of alien robots.