Acnologia Dragneel, also known simply as Acnologia, is one of the main antagonists in the anime and manga series Fairy Tail. Once a human Dragon Slayer, he became known as the Dragon King after transforming into a dragon himself. Acnologia is infamous for his immense power, destructive nature, and his hatred towards both dragons and humans. His role in the series is that of a formidable adversary, ultimately threatening the existence of both humans and dragons with his overwhelming strength and merciless demeanor.