Den Den Mushi appear in Eiichiro Oda's One Piece, which began as a manga in 1997 and as an anime in 1999, as living snails that function like telephones across the Grand Line. Different types handle calls, broadcasts and surveillance, with their facial expressions often mimicking the speaker. Clips of their ringing have circulated in anime edits, soundboards and fan videos, where the familiar call instantly identifies a One Piece reference without any dialogue. Its continued popularity comes from that instant recognition and from how easily the loop works as a ringtone or transition.