Item from Undertale / Deltarune by Toby Fox
Floating skull-shaped cannons that fire devastating laser beams — Sans's signature weapon, named after a scientist who doesn't officially exist.
Gaster Blasters are Sans's most powerful attack during his Genocide Route boss fight — floating skulls that fire devastating laser beams in patterns the player must dodge. They are named 'Gaster Blasters' in the game's code, connecting Sans to W.D. Gaster through their very existence. The name is never spoken in-game — it exists only in the code, making it a meta-clue about the relationship between Sans, Gaster, and the scientific experiments that may have given Sans his unique abilities. They are among the most iconic attacks in indie gaming.
Large, floating skull-shaped devices — white with dark eye sockets that glow before firing. They resemble animal skulls (possibly dragon or canine) and hover in the air at Sans's command. When they fire, a massive beam of energy erupts from their mouths.