Musnad Ahmad 30:3724

'Ali ibn Hafs narrated to us, Waraqa informed us, from Abu al-Zinad, from al-A'raj, from Abu Hurayrah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "The treasure of one of you will be, on the Day of Resurrection, a bald-headed serpent (shuja' aqra'). Its owner will flee from it, and it will pursue him until it makes him bite its fingers."