From Sahih Bukhari (Hadith 2929):
Narrated Abu Huraira:The Prophet (ﷺ) said, "The Hour will not be established till you fight with people wearing shoes made of hair. And the Hour will not be established till you fight with people whose faces look like shields coated with leather. " (Abu Huraira added, "They will be) small-eyed, flat nosed, and their faces will look like shields coated with leather
Reference: Bukhari 2929