Grissom was a Gamorrean who possessed a strong moral compass and a dignified nature.
Throughout his life, Grissom witnessed the violent deaths of the majority of his Gamorrean comrades in combat, resulting in several prominent scars along the left side of his face. Later in life, his wife and daughter tragically succumbed to a deadly disease, and he held them both as they died in his arms. Bereft of his family, Grissom embarked on a mercenary career, finding employment with Jabba Desilijic Tiure for a period.
Following Jabba's demise during Luke Skywalker's mission to rescue Han Solo, Grissom once again found himself adrift and without a clear direction. He spent some time traversing the galaxy, accepting any available work, ultimately finding himself working as a pitfighter on the planet of Otunia. One evening, while in a local cantina, a Gran was bothering a young Human female named Arista Kabul, causing Grissom to spill his beverage. Despite Grissom's initial attempt to ignore the disturbance, the Gran continued to provoke him, leading to Grissom's pent-up frustrations erupting. Grissom incapacitated the Gran, instigating a brawl. Local security forces apprehended Grissom, compelling him to work at the quarry owned by Arista's influential father.
A week after this event, Arista's uncle, Seth Kabul, who had formed an alliance with the failing Galactic Empire, attempted to murder Arista's father by placing a powerful explosive device in the quarry, timed to detonate during Lord Kabul's inspection. Grissom survived the blast and rescued Arista's life. Her father, fatally wounded, implored Grissom to safeguard Arista and assist her in leaving the planet. Holding an unconscious Arista, Grissom was reminded of the feelings of helplessness he experienced when his daughter passed away in his arms years before.
With the assistance of a Jawa named Tek, Grissom and Arista eventually succeeded in sabotaging Seth's operation and escaping the planet. Within this unlikely group, Grissom's life was imbued with renewed purpose, and Grissom acquired two invaluable companions.