Pluto barking comes from Five Nights at Treasure Island, a fan-made horror game inspired by Five Nights at Freddy's that reimagines familiar cartoon characters as unsettling threats. In that setting, a normally friendly dog bark becomes a warning that something is nearby, which is why the clip is often shared alongside a FNAF Jumpscare Scream in horror edits and soundboard collections. Fans of the wider FNAF community reuse it because it is instantly recognisable, very short, and easy to drop into gameplay videos, reaction clips, and meme edits without losing its impact.