Ren is the son of the Keetoowah chief Coatl and Sterope, one of the Pleiades. Zeus was jealous, so Sterope couldn't raise Ren herself. She entrusted his care to Artemis, who had the demoness Ravenna suckle him. After a year, she turned him over to Coatl, who shunned him. He was named Makah'Alay ("demon-crow") and the whole tribe scorned him. Ren was constantly compared to his younger brother Anukuwaya ("Coyote") and found lacking. His only friend was Buffalo, who was indebted to him for feeding his family when they were ill.

When Ren was a young man, fell in love with Windseer, handmaiden of the evil Grizzly Spirit. She goaded him into allowing the Grizzly Spirit into himself. While possessed by the spirit, he brought much suffering and death to the earth until the First Guardian captured him. The battle lasted a year and a day; the scar from the battle is known as the Grand Canyon today. The First Guardian banished the Grizzly Spirit back into the West Lands behind a gate. Then he placed the Grizzly Spirit's eight plagues into jars and appointed four Guardians to protect them. Ren became the Guardian of the East.

Coyote was engaged to the beautiful woman Butterfly until she fell in love with the Guardian Buffalo. Coyote killed him out of jealousy, so she called The Avenging Spirit and told him to take Coyote's heart. At the last minute, Coyote put his brother Ren in his own place. He stole the role of Guardian after his brother died.