Musnad Ahmad 792:32

Yahya ibn Sa'id narrated to us, from Bahz ibn Hakim, my father narrated to me, from my grandfather, he said: I heard the Messenger of Allah, peace and blessings of Allah be upon him, saying: "No man comes to his master (or patron) asking him for some of the surplus he has, and he refuses him, but that a bald-headed serpent (shuja') will be summoned for him on the Day of Resurrection, licking its lips, [representing] the surplus that he withheld."