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 comes to his mawla (kinsman) and asks him for some of his surplus wealth and he withholds it from him, Allah Almighty will make that withheld surplus wealth of his into a bald serpent on the Day of Resurrection."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17029