Character from Winx Club by Iginio Straffi / Rainbow S.r.l.
Prince of Andros turned tyrant of the seas — Aisha's cousin who absorbed dark pollution to become a monstrous sea creature, declared war on the entire ocean realm, and proved that villainy in the Winx universe sometimes comes from family.
Tritannus was a prince who felt overlooked and entitled — a dangerous combination. When exposure to toxic pollution from the human world mutated him, he embraced the transformation as the power he always deserved. He's petty in a way the bigger villains aren't: his grudge is personal and familial, rooted in jealousy of his brother Nereus and resentment toward Aisha's side of the royal family. He allied with the Trix (specifically Icy, who saw in him a useful tool), and together they terrorized the oceans and sought the Emperor's Throne — a seat of power over all ocean realms. His villainy is effective because he knows Andros intimately, knows where the defenses are weakest, and has no qualms about destroying the home he grew up in.
Originally a merman prince with dark skin and regal aquatic features. After his transformation: a monstrous sea creature with sickly green skin, tentacle-like appendages, and a trident that channels dark ocean magic. His eyes glow with corrupted power. The pollution that transformed him left visible toxic markings across his body. His presence contaminates the water around him.