Artist rendition of the turtle Kim Quy giving Lê Lợi the mythical sword, Thuận Thiên.
Kim Quy is a golden turtle demi-god of the Thanh Giang River, and is believed to have lived in Hoàn Kiếm Lake near Cổ Loa of modern-day Hanoi.
The first time Kim Quy is mentioned in history was during the reign of the An Dương King where Kim Quy appeared before the king while standing atop of the lake, and eventually gave one of his claws to the king with which an enchanted ballista was made to help the king protect his kingdom of Âu Lạc.
The second revelation of Kim Quy was sixteen centuries later, where he bestowed the legendary sword Thuận Thiên to help Lê Lợi rebel against Ming occupation of Đại Việt.