nisa-carittham vyathita-stana vyasur
vyadaya kesams caranau bhujav api
prasarya gosthe nija-rupam asthita
vajrahato vrtra ivapatan nrpa
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
In this way the demon Putana, very much aggrieved because her breast was being attacked by Krsna, lost her life. O King Pariksit, opening her mouth wide and spreading her arms, legs and hair, she fell down in the pasturing ground in her original form as a Raksasi, as Vrtrasura had fallen when killed by the thunderbolt of Indra.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Putana was a great Raksasi who knew the art of covering her original form by mystic power, but when she was killed her mystic power could not hide her, and she appeared in her original form.