Abdullah bin Umar reported,
The Prophet ﷺ said, "The one who does not pay the zakat on his wealth, Allah 
will make his wealth appear to him on the Day of Resurrection as a bald serpent with two black spots above its eyes. It will then cling to him, wrap itself around his neck, and say, 'I am your treasure, I am your treasure.'"
Ahmad 5729
Sahihحدثنا حجين بن المثني حدثنا عبد العزيز بن عبد الله بن أبي سلمة عن عبد الله بن دينار
عن ابن عمر
عن النبي ﷺ قال إن الذي لا يؤدي زكاة ماله يمثل الله عز وجل له ماله يوم القيامة شجاعا أقرع له زبيبتان ثم يلزمه يطوقه يقول أنا كنزك أنا كنزك
Its isnad is sahih. Hujayn bin Muthanna, his reliability was established earlier at 804. Abdul-Aziz is Ibn Majishun. The hadith was narrated by Nasai 1:343 through Abu Nadr from Ibn Majishun. Munziri mentioned it in Targhib wa Tarhib 1:269 and said, Nasai narrated it with a sahih isnad. Munziri also said, "the two zabibatayn" refers to the two lumps of foam at the corners of the mouth, though it is also said they are the two black spots. A similar meaning has already appeared in the hadith of Ibn Masud at 3577, where it was explained as referring to the bald serpent, and see also what comes later in the Musnad of Jabir at 14494.