Peabody's Improbable History - Lucretia Borgia - S1.E34

Lucretia Borgia, the world's best poison artist has just gotten a 12th husband who is snacking on furniture. Peabody and Sherman try to get the husband to leave Lucretia but he loves her too much to bail out on her. So, Peabody creates a special potion for him that will make the man impervious to poison so he will live and not leave his wife.