Run!

"Run!" is the 32nd track in the Undertale Soundtrack. This track plays while in pursuit by Undyne in Waterfall. This occurs while running along bridges, and Undyne is throwing spears or having spears stab out of the ground while pursuing either north or below the protagonist. It also plays whilst running from Undyne during her battle.

Trivia

 * The song is called 'mus_undynefast' in the game files.