Working as a cowboy and bounty hunter, Mountain Tim is announced as a leading competitor in the Steel Ball Run. During the first stages of the race, Tim becomes one of Johnny and Gyro's allies. He is also a Stand user and is able to shift through his lasso with his ability, Oh! Lonesome Me.

Mountain Tim is a man of average to above-average height, average build and has light hair. He later acquires a scar crossing his face.

He wears a stereotypical range of cowboy attire; his hat has a zebra print with a miniature cow's skull as a decoration, while the clothing on his upper torso is coated with a leopard print, his belt gun holster, and his scarf has a leopard print. He wears a sheriff's badge in the shape of a five-pointed star on his left side.

Mountain Tim is introduced as a benevolent bounty hunter who is well acquainted with the law and is stated to have made many friends. Although he participates in the Steel Ball Run, Tim quickly abandons his goal to give chase to a participant assassinating the competition. It seems his benevolence is such that horses intuit a sense of great respect for him, bowing their heads when he approaches. At the moment of his death, Mountain Tim confesses that he never expected to die a peaceful death but longed for at least a place to return after his journey.