The Messenger of Allah ﷺ said, "Whoever Allah has given wealth and does not pay its zakat will have his wealth made to appear to him on the Day of Resurrection as a bald serpent with two black spots above its eyes. It will be placed around his neck like a collar, then it will seize him by his jaws, meaning the sides of his mouth, saying, 'I am your wealth, I am your treasure.'" The hadith continues.
قال رسول الله ﷺ: من آتاه الله مالا، فلم يؤد زكاته مثل، له ماله شجاعا أقرع، له زبيبتان يطوقه يوم القيامة، يأخذ بلهزمتيه- يعنى بشدقيه- يقول: أنا مالك أنا كنزك… الحديث.
Bukhari narrated it in tafsir (4565) from Abdullah bin Munir, who heard Abu Nadr, who said, "Abdul-Rahman narrated to us," meaning Ibn Abdullah bin Dinar, from his father, from Abu Salih, from Abu Hurairah, who mentioned it.