Nerimer has very long orange hair and blue eyes. Her hair intricately tucked into two ponies on the sides of the head. On the head is decorated with blue crystal. He also wears earrings with light pink shells. She has sky blue wings.
Under the effects of Valtor's magic, Nerimer was aggressive and wild. But upon being turned back to normal Nerimer is calm, very gentle and sweet mermaid. She is very innocent and shy.
Nerimer is one the mermaids who is captured by Valtor's evil spell. Valtor places his mark on her; stealing her magic and changing her into mer-monster that attacked anything that crossed their paths. She appears in the episode The Sea of Fear as mer-monster. After Valtor's defeat, Nerimer's magic returned, she became a normal mermaid again and she returns home to the Underwater Kingdom.
Nerimer appears again in "The Enchanted Island," as the Guardian of Tir Nan Og took the form of three mermaids from Andros: her alongside Coralia and Talassia. Nerimer lures Aisha out into the water. After Aisha introduces herself, Coralia pushes Aisha underwater and with her fight against Winx in dungeon.