Please be sure to show your support for Toby Fox by listening to his music here: https://materia.to/undertaleID
The song megalovania, from the indie RPG undertale.
This is a recurring theme in his work. It originated in his Earthbound Halloween hack as the final boss theme and since then has made appearances in his other musical works, like Homestuck
Toby Fox is the amazing composer who created this master piece.