Snarling is a real animal warning signal made by dogs, big cats and other mammals when they pull back their lips, bare their teeth and force air through a tense throat. Recorded snarls like this one have become a staple sound effect in films, games and online videos because the meaning is understood instantly across languages. Editors reuse it for werewolves, guard dogs, zombies and angry creatures, and it keeps circulating on soundboards as a quick way to add aggression or danger to a short clip.