Vishrava Grants Boons to the Three Rakshasis
Kubera, knowing his father Vishrava is angry with him, sends three rakshasis to serve the sage. They rival each other in dancing and singing to please him. Vishrava is pleased and grants each a boon — and from these three women are born the lords of the rakshasas: Ravana, Kumbhakarna, Vibhishana, Khara, and Shurpanakha.
The sage Vishrava was born from half of Pulastya's body, out of his anger. He glanced at his son Vaishravana — Kubera — with great anger. Kubera, lord of the rakshasas, knew his father was furious with him. He tried always to please him.
Living in Lanka, the lord of the yakshas sent three rakshasis to serve his father. They were always ready to satisfy the great-souled rishi and were skilled in dancing and singing. Their names were Pushpotkata, Raka, and Malini. They were slender of waist and rivalled each other in trying to do their best.
Being pleased with them, the great-souled lord granted them boons. As they desired, he gave each of them a son, equal to a guardian of the world.
Pushpotkata gave birth to two sons who were the lords of the rakshasas — Kumbhakarna and Dashagriva, unmatched on earth in strength.
Malini gave birth to a single son named Vibhishana.
Raka gave birth to twins — Khara and Shurpanakha.
Vibhishana surpassed all of them in beauty. He was immensely fortunate and always performed rites of dharma. Dashagriva was the eldest of them all and was a bull among the rakshasas — immensely energetic, immensely valorous, immensely spirited, and brave. Kumbhakarna surpassed all of them in strength. He was a terrible stalker of the night and was frightening in battle because of his skills of maya (illusion). Khara was powerful in the use of the bow, hated brahmanas, and ate raw flesh. The terrible Shurpanakha always used to obstruct religious rites.
All of those brave ones were learned in the Vedas and all of them were good in the observance of their vows. They lived with their father on Mount Gandhamadana. Aranyaka Parva, Chapter 556