It is narrated from Sayyiduna Abdullah bin Amr (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "A servant is recorded as a believer for ages, then for ages, and then he dies while Allah is displeased with him; and a believer is recorded as a disbeliever for ages, then for ages, and then he dies while Allah is pleased with him. Whoever dies slandering and finding fault with people, his mark on the Day of Resurrection will be that Allah brands him on the snout, together with both lips."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 13757