Gaster Blasters come from Undertale, the 2015 role-playing game by Toby Fox, where they appear as part of Sans's notoriously difficult boss battle near the end of the Genocide Route. The floating, dragon-like skulls fire beams at the player, and their distinctive firing sound became closely linked with Sans himself. As Undertale clips, remixes and fan animations spread across YouTube and TikTok, the blast became a shorthand for an unstoppable attack or a sudden power reveal. It remains popular because it instantly signals danger, confidence and a boss-level threat.