Markandeyapurana 48.21

48.21

tān dṛṣṭvā hyapriyeṇāsya keśāḥ śīryanta vedhasaḥ /
samārohaṇahīnāśca śiraso brahmaṇastu te //

When the creator Brahmā saw them, the hair of his head through his displeasure grew withered[8] and lost its erectibility.[9] Through its downward gliding[10] it became the Serpents,[11] and from its loss[12] of credibility they are known as the Ahis or Snakes. Thereupon in anger at having seen the Serpents, he fashioned beings possessed with anger;[13] they were born as the flesh-eating demons, tawny-hued and fierce.