Docky exists as a plastic model skeleton by day, becoming animated at night. His face mirrors a human skull with hollows instead of ears and a nose, featuring orange eyes that leak a black, ink-like substance. He always wears a red firefighter helmet bearing stitch repairs and the number 13, paired with a white-and-red striped shirt displaying a large yellow "D" on the front.

Personality-wise, he displays arrogance and self-importance, largely fueled by pride in his unique ability, which occasionally irritates classmates as seen in "Strange Scribbles." Nevertheless, he proves dependable and willing to help others. Viewed as one of the more mature students, he takes satisfaction in this perception. Official notes describe him as a loner envied by other boys for his special power and his speed sliding down the school's staircase banister. Girls regard him with curiosity, though he shows no reciprocation of romantic interest. His closest bond is with Quicky, who greatly admires him and frequently times his banister slides. Their dynamic presents an odd pairing between Docky's typically stoic nature and Quicky's energetic personality.

He exhibits a distinct quirk of frequently adjusting his helmet's brim. His obsession with speed manifests primarily through competitive banister sliding, where he constantly strives to improve his recorded times. This fixation extends to a berserk button—being called slow provokes a strong reaction. Instances of poor judgment occur, like impulsively attacking Johnny Crow high above ground without considering the danger of falling, leading to regret. While fundamentally possessing a good heart, he occasionally succumbs to aggressive outbursts, notably in "Noisy Noisy" where he lashes out at both Noisy for trying to protect him and the bully trio for framing him, culminating in using his whirlwind ability to force them into an elevator.

His signature ability, "Whirlwind Forever," generates extreme speed and creates a substantial whirlwind. This power serves dual purposes: potentially destructive under specific conditions or functioning as a valuable tool for solving school problems, reflecting his complex role. Character development occurs across episodes: "Speedster E" explores a body swap with Enton, temporarily altering their personalities and perspectives; "Fly! Golden Eye" highlights his capacity for remorse and underlying kindness after the Johnny Crow incident; "Noisy Noisy" illustrates his capacity for anger and protectiveness, revealing layers beneath his cool exterior.