Hiuen Tsang, in his passage of the Desert, both outward and homeward, speaks of visual illusions; such as visions of troops marching and halting with gleaming arms and waving banners, constantly shifting, vanishing, and reappearing, “imagery created by demons.”  A voice behind him calls, “Fear not! fear not!” Troubled by these fantasies on one occasion, he prays to Kwan-yin (a Buddhist divinity); still he could not entirely get rid of them; but as soon as he had pronounced a few words from the Prajna (a holy book), they vanished in the twinkling of an eye.

These Goblins are not peculiar to the Gobi, though that appears to be their most favoured haunt.  The awe of the vast and solitary Desert raises them in all similar localities.  Pliny speaks of the phantoms that appear and vanish in the deserts of Africa; Aethicus, the early Christian cosmographer, speaks, though incredulous, of the stories that were told of the voices of singers and revellers in the desert; Mas’udi tells of the Ghuls, which in the deserts appear to travellers by night and in lonely hours; the traveller, taking them for comrades, follows and is led astray.  But the wise revile them and the Ghuls vanish.  Thus also Apollonius of Tyana and his companions, in a desert near the Indus by moonlight, see an Empusa or Ghul taking many forms.  They revile it, and it goes off uttering shrill cries.  Mas’udi also speaks of the mysterious voices heard by lone wayfarers in the Desert, and he gives a rational explanation of them.  Ibn Batuta relates a like legend of the Western Sahara:  “If the messenger be solitary, the demons sport with him and fascinate him, so that he strays from his course and perishes.”  The Afghan and Persian wildernesses also have their Ghul-i-Beaban or Goblin of the Waste, a gigantic and fearful spectre which devours travellers; and even the Gael of the West Highlands have the Direach Ghlinn Eitidh, the Desert Creature of Glen Eiti, which, one-handed, one-eyed, one-legged, seems exactly to answer to the Arabian Nesnas or Empusa.  Nicolo Conti in the Chaldaean desert is aroused at midnight by a great noise, and sees a vast multitude pass by.  The merchants tell him that these are demons who are in the habit of traversing the deserts. (Schmidt’s San.  Setzen, p. 352; V. et V. de H. T. 23, 28, 289; Pliny, VII. 2; Philostratus, Bk.  II. ch. iv.; Prairies d’Or, III. 315, 324; Beale’s Fahian; Campbell’s Popular Tales of the W. Highlands, IV. 326; I.  B. IV. 382; Elphinstone, I. 291; Chodzko’s Pop.  Poetry of Persia, p. 48; Conti, p. 4; Forsyth, J. R. G. S. XLVII. 1877, p. 4.)