Harriet Bree

Though, based on your reaction time, I’d say I’m a little faster.

Harriet Bree  is a member of the Ace-Ops Specialist team, first appearing in "The Greatest Kingdom ". Her weapons of choice are the Fast Knuckles.

Appearance
Harriet is a young girl with platinum blonde and brown hair shaved on the sides and violet eyes. She wears a very short-sleeved Atlesian Specialist uniform that consists of a sleeveless white vest, a rolled up blue shirt, a red tie and white shorts. The blond portions of her hair rest in a pattern that resemble a rabbit's ears.

Personality
Harriet is competitive and quick witted in nature. This personality causes her to only be loyal to those who earn her respect, as seen with her interactions with Ruby Rose and the similarities in their Semblances. However, she is still cordial and well-mannered.

Harriet also enjoys teasing others, particularly poking fun at Marrow Amin and his antics. She is quick to rush into action.

History
Harriet and her team were called down to Mantle in response to reports of a stolen Atlesian airship entering its airspace followed by the unauthorized use of weapons by civilians. The culprits were Team RWBY, Jaune Arc, Nora Valkyrie, Lie Ren, Qrow Branwen and Oscar Pine, who defended the city from a pack of Sabyrs. Harriet and her team caught them by surprise and seized their weapons before leaving them in the custody of the authorities.

Following their release of their quarries, Harriet and the rest of Ace-Ops apologize for the miscommunication, before the students are introduced to Atlas Academy by Penny Polendina.

In the mission to the abandoned Schnee Dust Company mine, Harriet and Marrow join Team RWBY in the mines. Marrow complains about being signed up as a babysitter, to which Harriet deflects, claiming that's what the rest of the Ace-Ops are to him.

Harriet and Ruby Rose discuss their Semblances, where she believes she may be faster than Ruby. She then defeats the Geist in the caves, alongside the rest of Ace-Ops. However, one Dust crystal she attempts to catch is instead snagged by Ruby, Harriet witnessing her semblance, and commenting that there seems to be more to it than simply speed.

Powers and Abilities
She is a skilled fighter, as she is a member of the Atlesian Special Operatives unit, the most elite group of Huntsmen and Huntresses in Remnant.

Harriet's Semblance allows her to run at super-speed, accompanied with an electric trail. She believes she has a better reaction time than Ruby Rose.

Her weapons of choice are the Fast Knuckles, an exoskeleton suit whose main function seems to be its ability to greatly enhance the wearer's upper body strength. They pack enough of a punch to smash a rocky cave wall to dust and destroy a grimm in a single uppercut.

Trivia

 * Like other members of the Ace-Ops team, Harriet is likely based on the Aesop's Fable, particularly the Hare from The Tortoise and the Hare.
 * The name Harriet means "keeper of the hearth." This brings golden and brown colors to mind.
 * Harriet was designed by concept artist Erin Winn.