The exact source of this 'nyam' clip is unclear from the available details, so it is best understood as a short meme-style eating sound used across soundboards and quick video edits. Sounds like this spread because they communicate a bite, nibble or playful chomp in under a second, which is perfect for short-form comedy. It stays useful because creators can drop it onto food clips, character reactions, pet videos and visual gags without needing viewers to know any specific reference.