Etrigan the Demon is a powerful, demonically possessed anti-hero in the DC Comics universe, who appears in Batman: The Animated Series. Bound to the human Jason Blood, Etrigan is characterized by his rhyming speech and fiery personality. As a demon from Hell, Etrigan possesses superhuman strength, immortality, and magical abilities. In the series, he often assists Batman in dealing with supernatural threats, providing a unique blend of brutal force and mystical knowledge. Despite his demonic nature, Etrigan often sides with heroes, making him a complex character who straddles the line between good and evil.