Dark Water (Punkcoa)

Venus is one of the most feared, hated and misunderstood creatures in the land: a Kelpie. After Nero, the water god who created the Kelpies gets imprisoned, Venus hides on an island with her son. One day, her son dies in a tragic accident, and Venus suddenly finds herself on a journey to bring him back. Along the way, she'll have to face dangers, enemies, and make new friends.
Source: Webtoon