‘Amr b. Al-‘Âs was once walking with a group of his friends, when he passed by the bloated, rotting carcass of mule. He said: “By Allah! To eat your fill from this carcass is better than eating the flesh of a Muslim (by backbiting him).”
Al-Bukhârî, Al-Adab Al-Mufrad. Shaykh Al-Albânî (Sahîh Al-Adab Al-Mufrad p266) said this narration’s chain of narration is sahîh.