Kilmo existed as a male individual within Coronet City, located on the planet of Corellia, at the time the Galactic Empire was in reign. In the year of 13 BBY, Kilmo crossed paths with the criminal Han Solo, and this encounter resulted in him sustaining a bruise under his left eye.
The character of Kilmo was initially established in the 2018 reference book titled Solo: A Star Wars Story The Official Guide, authored by Pablo Hidalgo. While Mur Lafferty's Solo: A Star Wars Story: Expanded Edition described him as human, his subsequent appearance in the first issue of the Marvel comic adaptation of Solo: A Star Wars Story presented Kilmo as an alien being.