It is narrated from Sayyiduna Mu'awiyah bin Haydah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Whoever is asked by a mawla (kinsman) for some of his surplus wealth and withholds it from him, on the Day of Resurrection that very surplus wealth which he had will come to him in the form of a bald serpent."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17028