Triton

Tritons are magical creatures with the upper half of a human and the lower part of a fish, similar to mermaids. However unlike mermaids who possess Fairies}fairy-like wings, they appear to have a single fin found over the backbone in promotional images and videos. Tritons will appear in Season 5.

The only triton known so far is Tritannus, who is Aisha's cousin, and will become the season's main villain after being turned into a monster by pollution due to an oil spill on Earth. The Winx will have to go on a quest to find the ancient Sirenix power to fight him because their Believix powers are too weak to fight Tritannus underwater.