In this life, an envious person commits violent acts against many living entities. Therefore after his death, when he is taken to hell by Yamaraja, those living entities who were hurt by him appear as animals called rurus to inflict very severe pain

Expressions researched:
"In this life, an envious person commits violent acts against many living entities. Therefore after his death, when he is taken to hell by Yamarāja, those living entities who were hurt by him appear as animals called rurus to inflict very severe pain upon him"

Srimad-Bhagavatam

SB Canto 5

In this life, an envious person commits violent acts against many living entities. Therefore after his death, when he is taken to hell by Yamarāja, those living entities who were hurt by him appear as animals called rurus to inflict very severe pain upon him.

SB 5.26.11, Translation and Purport

In this life, an envious person commits violent acts against many living entities. Therefore after his death, when he is taken to hell by Yamarāja, those living entities who were hurt by him appear as animals called rurus to inflict very severe pain upon him. Learned scholars call this hell Raurava. Not generally seen in this world, the ruru is more envious than a snake.

According to Śrīdhara Svāmī, the ruru is also known as the bhāra-śṛṅga (ati-krūrasya bhāra-śṛṅgākhya-sattvasya apadeśaḥ saṁjñā). Śrīla Jīva Gosvāmī confirms this in his Sandarbha: ruru-śabdasya svayaṁ muninaiva ṭīkā-vidhānāl lokeṣv aprasiddha evāyaṁ jantu-viśeṣaḥ. Thus although rurus are not seen in this world, their existence is confirmed in the śāstras.