Song That Might Play When You Fight Sans is the 72nd track in the Undertale Soundtrack. It is similar to a sped up version of the song "sans." This song, contrary to its title, is unused, and Toby Fox may have added it to the soundtrack to misguide players into believing that Sans would have a battle at some point in the Neutral Route.
- This song is not in the game files.
- Much of this song is made with instruments from the SNES versions of Mega Man X2 and Mega Man X, particularly their iconic guitar sounds.