Fennel has long blue, almost dark, hair and eyes, and wears glasses. She is cheerful, naive and innocent, to the point of adorable cuteness. She is very sensitive, tender and emotional to the point of crying at times. She is very bubbly and energetic, with a passion for her work, and is socially inept, often stuttering at times. However she is brilliant, curious and often has many new, fresh ideas no other person in her profession could have, and is often called insane by her peers.