From the Varaha Purana, as quoted by Kedaranath Dutt/Bhaktivinode Thakur in his book "Jaiva Dharma”:
Raksasah kalim ashritya
Jayante brahma-yonishu
"In the Kali-yuga, demons take birth in the families of brahmins."
This idea of beings from other realms taking birth on Earth with agendas is not unheard of. In the tenth canto of Shrimad Bhagavatam, Shree Vishnu instructed the demigods to take birth ahead of the Krishna avatar in order to assist Him in His pastimes--
http://www.holloworbs.com/rakshasha_influence.htm
Cheers!