Metal Sonic first appeared in Sonic CD in 1993 as Dr Eggman's robotic counterpart to Sonic, designed to match his speed and challenge him as a mechanical rival. Fireball and energy attack effects became closely linked to the character in later games and fan edits, where his attacks are often paired with metallic charging and explosive launch sounds. Online, creators reuse those effects outside gameplay for memes, animations and short edits, keeping the sound popular as a quick signal of a robotic boss powering up for an attack.