Selkie

The Piscies are magical creatures that appear in Season 5.

Overview
The Piscies are small magical creatures that guard the portals connecting the Ocean of Andros to the oceans of all the realms of the magical dimension. They have the power to open or close the portals that link the Ocean of Andros to the oceans of another realm and there is one gatekeeper for each realm.

There are often many round creatures looking like baby fish that accompany them which turn onto brightly colored fish on coming in contact with magic or other fish.

History
The Piscies were first seen in The Spill during the crowning of Nereus, when Leny was holding the crown that King Neptune would place on Nereus's head.

After an oil spill occurred on Earth near Gardenia, oil from the spill traveled through the sea and reached the underwater portal linking the ocean of Earth to that of Andros. Fella was alerted by a triton guard and tried to stop the oil from crossing the portal in vain and sealed the Earth portal after crossing it into Andros with the triton guard.

There she and Leny saw Tritannus being mutated into a monster after absorbing the pollution and breaking free from the prison of Andros along with the Trix. With the help of the Trix and of the triton guards that he turned into monsters loyal to him, Tritannus stole the powers of the two gatekeepers. He then vowed to hunt down every Piscies and to steal all their powers, so that he would be able to enter the Infinite Ocean and from there conquer the whole Magic Dimension.

Appearance
The Piscies of the Oceans look like miniature wingless mermaids with brightly colored skin. They wear hats that are brightly colored like them and which have decorations and a kind of veil on the back. They are colored like the respective planets which they guard.

Trivia

 * The Piscies have been rumored to be the underwater equivalents of the Pixies.
 * The Piscies bear a certain resemblance to the Pixies and, due to their mermaid-like appearance and their small size, look like the Water Nymphs living in the Black Mud Swamp from Season 1