Batman's main opponent is the Joker, a deranged supervillain known for his ruthless and merciless nature. With his uncanny ability to exploit the weaknesses of his opponents and turn their own weapons against them, the Joker strikes fear into the hearts of criminals. His eerie aura and nightmarish reputation inspire awe and terror. Additionally, the Joker's signature weapon is the Bang, a modified firearm that shoots out a flag with the word "Bang" on it, symbolizing his twisted sense of humor.