What was the name of the snake sacrifice performed by Janamejaya?

The snake sacrifice performed by Janamejaya was called Sarpasatra, also written Sarpa Satra.

In the Mahabharata tradition, Janamejaya organized the ritual to destroy the serpent race after his father, King Parikshit, died from the bite of the serpent king Takshaka. The sacrifice used ritual chants and offerings into a sacred fire; snakes were magically drawn toward it and consumed.

The ceremony was not completed. Takshaka sought protection from Indra, while the young sage Astika intervened on behalf of the serpents. Janamejaya granted Astika a boon, and Astika asked him to end the sacrifice. The king eventually agreed, allowing Takshaka and the remaining serpents to survive.

Sarpasatra is sometimes translated simply as the “snake sacrifice,” which can make the answer look like a description rather than a proper name. It should not be confused with Vajapeya, Rajasuya, or Ashvamedha, which are different Vedic royal rituals. The episode is associated especially with the Mahabharata’s account of revenge, restraint, and the preservation of the Naga lineage.