Sayyidah Sarra' bint Nabhan al-Ghanawiyyah (may Allah be pleased with her) narrates: Our slave Nusayb asked the Prophet (peace and blessings be upon him) about snakes: which of them should be killed? She says: I heard the Prophet (peace and blessings be upon him) say: Kill whichever of them appears, whether it is large or small, black or white, for whoever of my Ummah kills one, it will be his ransom from Hellfire, and whoever is killed by one (a snake) will be a martyr."
Al-Tabarani recorded it in al-Mu'jam al-Kabir; its chain contains a narrator, Ahmad bin al-Harith al-Ghassani, and he is matruk (abandoned).