Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) narrates that a man drank from the mouth of a waterskin and a small snake slipped into his stomach, so the Messenger of Allah (peace and blessings be upon him) forbade folding back the mouths of waterskins and drinking from them.
Isma'il al-Makki has some weakness.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصداق / 14662