This article relies largely or entirely on a single source. (October 2015)
Iara, also spelled Uiara or Yara (Portuguese pronunciation: [iˈjaɾɐ], [iˈaɾɐ], [ˈjaɾɐ], [wiˈjaɾɐ], [ujˈjaɾɐ]) or Mãe das Águas ([ˈmɐ̃j dɐˈz aɣwɐs], "mother of waters"), is a figure from Brazilian mythology based on ancient Tupi and Guaraní mythology. The word derives from Old Tupi yîara = y + îara (water + lord/lady) = lady of the lake (water queen). She is seen as either a water nymph, siren, or mermaid depending upon the context of the story told about her. The Brazilian town of Nova Olinda claims the Cama da Mãe D’água as the home of Iara.
Iara is a beautiful young woman, sometimes described as having green hair, light brown or copper-colored skin (as that of an Indigenous Amerindian from Brazil, or of a caboclo) and brown eyes, connected to a freshwater dolphin, manatee or fish body (the Tupi word y did not have a distinct meaning, being used in general for any riverine or freshwater lacustrine place) who would sit on a rock by the river combing her hair or dozing under the sun. When she felt a man around she would start to sing gently to lure him. Once under the spell of the Iara a man would leave anything to live with her underwater forever, which was not necessarily a bad thing, as she was pretty and would cater for all needs of her lover for the rest of his life.
It is often claimed that, until the 18th century, the Iara legend was originally about an aggressive monstrous river merman known as Ipupiara ("freshwater monster", [ipupiˈaɾɐ] in Portuguese phonological rules; by that [Pre-Pombaline] time, most Brazilians still spoke línguas gerais), that would readily devour fishers, rather than that of a seducing, docile river mermaid.
Iaras are immortal (like the nymphs of Greek mythology), but her lovers do age and die, which means that they live most of eternity alone.
The legend of the Iara was one of the usual explanations for the disappearance of those who ventured alone in the jungle.
Iara (or Yara) is also a very popular female name in Brazil.
The Iara is similar in nature to several other female figures of folklore from other regions such as La Llorona from Mexico and the Southwestern United States, the Colombian creatures La Patasola and the Tunda and the Deer Woman of North America. All are females who at times function as sirens leading men to their death.
In the 1969 film version of the novel Macunaíma, the protagonist of the same name meets his death at the hands of an Iara. He embraces her eagerly and sees too late the blow hole in the back of her neck that gives her away as the creature she is and not the beautiful woman he mistook her for.
This physical deformity marking an otherwise perfect woman is a common theme among siren figures in the Americas but it is usually one of the feet. Deer Woman has hooves for feet, La Patasola and the Tunda have deformed feet and La Llorona is often said to have no feet by those who see her.