Rakshasa

A Rakshasa (Malay/Indonesian: raksasa, Bengali: rakkhosh, Assamese: raikhox) or alternatively rakshas, is a race of mythological humanoid beings or unrighteous spirit in Hindu and Buddhist religion. Rakshasas are also called man-eaters ("Nri-chakshas," "Kravyads"). A female Rakshasa is called a Rakshasi, and a female Rakshasa in human form is a Manushya-Rakshasi. Often Asura and Rakshasa are interchangeably used.

According to the Ramayana, Rakshasas were created from Brahma's foot; other sources claim they are descended from Pulastya, or from Khasa, or from Nirriti and Nirrita. Hinduism maintains that the Rakshasas were particularly wicked humans in previous incarnations. Rakshasas are notorious for disturbing sacrifices, desecrating graves, harassing priests, possessing human beings, and so on. Their fingernails are venomous, and they feed on human flesh and spoiled food. They are shapehangers, illusionists, and magicians.

Ellen Gives Info:

It's a race of ancient Hindu creatures. They appear in human form. They feed on human flesh. They can make themselves invisible and they cannot enter a home without, first being invited.

Rakshasa's live in squalor. They sleep on a bed of dead insects. 

They have to feed a few times, every 20-30 years. Slow metabolism. 

A dagger made of pure brass could kill it.