In the Mahabharata war, the Pandavas cannot defeat their teacher Drona. Bhima kills an elephant named Ashwatthama, which is also the name of Drona’s son, and shouts that Ashwatthama is dead. Urged by Krishna and Bhima, Yudhishthira, who never lies, confirms it.
In Kisari Mohan Ganguli’s translation, Yudhishthira “distinctly said that Aswatthaman was dead,” and said the word “elephant” indistinctly. Drona lost the will to fight and was killed.
The popular form of the line, Ashwatthama hatah, naro va kunjaro va, “Ashwatthama is dead, man or elephant,” is a later compression. It does not appear in the Sanskrit verses that tell the scene.