Katsuki is a young man of average height, with a slim, muscular build, and a fair skin tone. He has short, spiky, sandy blond hair with choppy bangs that hang over his eyebrows. His eyes are sharp and bright red in color. He showed to be extremely arrogant and condescending to those around him, often bragging of his Explosion Quirk's power, and even boasting that he would take on his entire middle school class.