Not to be confused with "Kripa" (Kṛpā), a female given name.
Kripa (Kṛpa in IAST transliteration), also known as Kripacharya or Krupacharya is an important character in the Mahābhārata, one of the seven Chiranjivi (the "immortals" who are to remain alive throughout the present age, the Kali Yuga).
He was the son of Shardwan and Janapadi, born in a particularly extraordinary manner (see below). He along with his sister Kripi were adopted by King Shantanu. Later on Kripa became an acharya, teacher of the royal children, giving him the name Kripacharya. He taught Kauravas and Pandavas siblings for many years, before Dronacharya was appointed for further education by Bhishma.His twin sister Kripi married Drona. 
From his early childhood, he was more interested in archery than in the study of the Vedas. He meditated and attained the art of all types of warfare. He was such a great archer that no one could defeat him.
This created panic amongst the gods. Especially Indra, the King of the Gods, felt the most threatened. He then sent a beautiful Apsara (divine nymph) from the Heaven to distract the celibate saint. The nymph, called Janapadi, came to the saint and tried to seduce him in various ways.
Shardwan was distracted and the sight of such a beautiful woman made him lose control. As he was a great saint, he still managed to resist the temptation and controlled his desires. But his concentration was lost, and he dropped his bow and arrows. His semen fell on some weeds by the wayside, dividing the weeds into two - from which a boy and a girl were born. The saint himself left the hermitage and his bow and arrow and went to the forest for penance.
Coincidentally, King Shantanu, the great-grandfather of the Pandavas, was crossing from there and saw the children by the wayside. One look at them was enough for him to realize that they were the children of a great Brahmin archer. He named them Kripa and Kripi and decided to take them back with him to his palace.
When Shardwan came to know of these children he came to the palace, revealed their identity and performed the various rituals which are performed for the children of Brahmins. He also taught the children archery, Vedas and other Shashtras and the secrets of the Universe.
The children grew up to become experts in the art of warfare. The boy Kripa, who came to be known as Kripacharya, was now assigned the task of teaching the young princes all about warfare.
On growing up Kripa was the chief priest at the court of Hastinapura. His twin sister Kripi married Drona, the weapons master to the court - who, like her and her brother, had not been gestated in a womb, but outside the human body.
- विभीषण:कृपश्चपरशुरामश्च सप्तैतेचिरंजीविन:।
- Varkey, C.P. (2001). A Pilgrimage ~ Through the Mahabharata. St Pauls BYB. pp. 22–. ISBN 978-81-7109-497-4.
- Sharma, Mahesh; Chaturvedi, B.K. (2006). Tales From the Mahabharat. Diamond Pocket Books (P) Ltd. pp. 42–. ISBN 978-81-288-1228-6.