When serpent worship became prevalent among the Aryans, the Nagas were regarded as demigods. They were occasionally “the friends of man”, and to those they favoured they gave draughts of their nectar, which endowed them with great strength. Their city was the Paradise of serpent worshippers. The female Nagas were beautiful nymphs, who were sometimes wooed by mortals. As the Asuras are the enemies of the gods, the Rakshas or Rakshasas are the enemies of man.[120] These demons are “night prowlers”; they have greatest power after “the first forty seconds of grey twilight preceding nightfall”. They travel faster than the wind, and go through the air; they have also power to change their shape. Sometimes they appear in the guise of tigers, bears, or great monkeys; and their hues vary from yellow to red, and blue to green. In the _Ramayana_ they are found associated with the Asuras of Ceylon; a spy enters a demon dwelling and sees them in all their shapes, some frightfully deformed, with small bodies and long arms; some as grotesque dwarfs, others as horrible giants with long projecting teeth; some with one eye, others with three eyes; some with one leg, two legs, or three, or even four; and some with heads of serpents, horses, or elephants. In the _Mahabharata_ the Rakshasas are like gorillas; they have arrow-shaped ears, big red eyes, and red hair and beards, and mouths like caves; they feast on human beings and cattle. The heroic Bhima, like Siegfried Dietrich of Bern, Beowulf, and Finn-mac-Coul, is a mighty slayer of these man-eating demons. They are impervious to weapons, but Bhima wrestles with them and breaks their backs or tears them asunder, after lively combats with trees and boulders. Female Rakshasas sometimes fall in love with human beings, and transform themselves into beautiful women. Bhima takes one for his bride, and she carries him through the air to a Celestial retreat among the mountains. [120] Asuras are sometimes called Rakshasas also. The most loathsome Rakshasas are the goblin-like Pisachas,[121] who are devourers of dead bodies in cemeteries, and are exceedingly vile and malignant fiends. They are the bringers of diseases and wasting fevers. In the _Atharvaveda_ Agni is invoked by the priests, who mutter charms over suffering and “possessed” mortals, to take the Pisachas between his teeth and devour them. They are “those who hound us in our chambers, while shouting goes on in the night of the new moon ... the flesh devourers, who plan to injure us, and whom I overcome”. The priest declares: “I plague the Pisachas as the tiger the cattle owners. As dogs who have seen a lion, these do not find a refuge.... From villages I enter Pisachas fly away.... May Nirriti (a goddess of destruction) take hold of this one.”[122] [121] _Pron._ pe-shatch'as. [122] Bloomfield's _Atharvaveda_ iv, 36 (_Sacred Books of the East_, vol. xlii).