As the human civilizations mastered the art of naval travel, stories from distant lands circulated across the Earth, merging with the old religious and folklore tales of old and forming new legendary creatures. One of such famous creatures is the South American myth of mermaid Iara (or sometimes called Uira and Yara) that has managed to gain great hold in the minds of the Brazilian people.
Created by combining ancient local myths about water snake spirits and possibly African goddesses of a Mami Wata and Yemaya, the Iara was mermaid like creature that was often called the "Mother of the Waters". She is described as a beautiful woman with green eyes, shinning hair and mesmerizing voice. As many mermaid myths across the world, Iara also had a dual nature. In one of her aspects, she often appeared sitting on the shores of the rivers and lakes (most famously in the Amazon regions) singing her enchanting songs. When he managed to attract unsuspecting males to her, she took them to the water where she agreed to spend their life with them. As she was immortal, she could not remain with their loved ones for long and generally spend the majority of their immortal existence in sadness, recollecting old and happy days.
However, she also had a darker nature which results in death of many people. Pretty much any misfortune of death in the vicinity of the water or deep woods is attributed to the Iara's influence, and natives of Amazonia (Brazil and Columbia) even today fear her and avoid water traveling or coming near a lake or river during the night. According to their beliefs, she is responsible for the deaths of thousands of people (pretty much everyone who got lost in the deep tropical woods is believed to have been enchanted by her song) and hundreds of destroyed ships.
The modern day view of Iara (very popular girl's name) has been established by Brazilian poet Gonçalves Diaz who named her by combining the two words from native Tupi language - "ig" meaning water and "iara" which means lord of lady. In addition to her female mermaid form, Brazilian natives also preserved mythos about her original snake spirit called Mboiaçu who is believed to be personification of "trouble makers" and misfortune.