"Megalovania" is an energetic and intense track featured in the indie video game "Undertale," created by Toby Fox. Originally composed for the EarthBound Halloween Hack in 2008, it was later used as the battle theme for the character Sans in "Undertale." The song's driving beat, catchy melody, and frenetic pace perfectly complement the intense battles encountered throughout the game. "Megalovania" has become one of the most recognizable and beloved tracks from the "Undertale" soundtrack, garnering praise from both fans and critics for its memorable composition and its ability to heighten the tension and excitement during gameplay.