Deltarune is an episodic role playing game created by Toby Fox, first released in 2018 as a follow up in spirit to Undertale. Its soundtrack and sound design use short, atmospheric stings to signal danger and story shifts, and fans soon isolated this ominous tone for use outside the game. Clips spread through gaming edits, memes and soundboards because the effect is instantly readable without context. It remains popular as a compact way to add tension to horror and comedy videos.