Indra beheads the three-headed priest Vishvarupa, carries the guilt for a year and divides it among earth, trees and women (and, later, water), each for a boon.
Vishvarupa is house priest of the gods and nephew of the Asuras, with heads for Soma, sura and food. He promises shares openly to the gods and secretly to the Asuras. Indra, afraid for his sovereignty, cuts off the heads, which become a hazel-cock, a sparrow and a partridge. He holds the guilt in his hand for a year, called Brahmin-slayer by all creatures. Earth, trees and a gathering of women each take a third in return for a boon: dug earth heals within the year, pruned trees sprout more, women obtain offspring. The marks are fissures, sap and the monthly courses, and the text turns each into a ritual rule.
After Brihaspati leaves the gods, Vishvarupa becomes their priest. He offers aloud to the gods and in secret to the demons, his mother's kin. Indra, afraid and angry, cuts off the three heads, which become a francolin, a sparrow and a partridge. He accepts the guilt, bears it a year and divides it in four: earth (deserts; pits fill), trees (sap; branches regrow), women (monthly courses; a boon of their own) and water (bubbles and foam; it increases what it is mixed with).
What is different here:
Four quarters instead of three thirds, with water added; the earth's mark is deserts, not fissures; a reason is given for Vishvarupa's priesthood; no ritual rules.
Indra kills the ascetic three-headed son of Tvashtri out of fear for his throne and has a carpenter cut off the heads. Only after Vritra is also dead does Vishnu prescribe a horse sacrifice, at which Indra divides the sin of Brahmin-killing among trees, rivers, mountains, the earth and women.
What is different here:
Five receivers, no boons named, the sharing follows a horse sacrifice and comes after the Vritra war; Vishvarupa is an ascetic rival, not a double-dealing priest.
Tvashtri's three-headed, six-eyed son drinks Soma with one mouth, liquor with another and eats with the third. Indra hated him and cut off the heads, from which a francolin, a sparrow and a partridge sprang. The text moves straight on to Tvashtri's revenge.
What is different here:
No priesthood, no secret shares, no guilt and no sharing-out.
Sources: The Veda of the Black Yajus School (Taittiriya Sanhita), tr. A. B. Keith (1914); Srimad-Bhagavatam (Bhaktivedanta Vedabase); The Mahabharata, tr. K. M. Ganguli (1883-96), sections read for the Vedic layer; The Satapatha-Brahmana, tr. Julius Eggeling (Sacred Books of the East 12, 41)