AKHLYS (Achlys) was the personified spirit (daimona) of the death-mist--the clouding of the eyes preceding death. She may also have been the goddess of deadly poisons. Akhlys was probably numbered amonst the Keres.
Probably a daughter of NYX, though nowhere stated
ACHLYS (Achlus), according to some ancient cosmogonies, the eternal night, and the first created being which existed even before Chaos. According to Hesiod, she was the personification of misery and sadness, and as such she was represented on the shield of Heracles (Scut. Herc. 264, &c.): pale, emaciated, and weeping, with chattering teeth, swollen knees, long nails on her fingers, bloody cheeks, and her shoulders thickly covered with dust.
Source: Dictionary of Greek and Roman Biography and Mythology.
CLASSICAL LITERATURE QUOTES
Hesiod, Shield of Heracles 264 ff (trans. Evelyn-White) (Greek epic C8th or C7th B.C.) :
"And beside them [the Keres (Deaths) and the Moirai (Fates) on the battlefield] was standing Akhlys (Achlys), dismal and dejected, green and pale, dirty-dry, fallen in on herself with hunger, knee-swollen, and the nails were grown long on her hands, and from her nostrils the drip kept running, and off her cheeks the blood dribbled to the ground, and she stood there, grinning forever, and the dust that had gathered and lay in heaps on her shoulders was muddy with tears."
Nonnus, Dionysiaca 14. 143 ff (trans. Rouse) (Greek epic C5th A.D.) :
"[Hera spies the nurses of the infant god Dionysos :] Hera, who turns her all-seeing eye to every place, saw from on high the everchanging shape of Lyaios (Lyaeus) [Dionysos], and knew all. Then she was angry with the guardians of Bromios. She procured from Thessalian Akhlys (Achlys, Death-Mist) treacherous flowers of the field, and shed a sleep of enchantment over their heads; she distilled poisoned drugs over their hair, she smeared a subtle magical ointment over their faces ,and changed their earlier human shape. Then they took the form of a creature with long ears, and a horse's tail sticking out straight from the loins and flogging the flanks of its shaggy-crested owner; from the temples cow's horns sprouted out, their eyes widened under the horned forehead, the hair ran across their heads in tuft, long white teeth grew out of their jaws, a strange kind of mane grew of itself, covering their necks with rough hair, and ran down from the loins to feet underneath."
- Hesiod, The Shield of Heracles - Greek Epic C8th - 7th B.C.
- Nonnus, Dionysiaca - Greek Epic C5th A.D.