"The Final Battle", also known as Fight with Lavos, is a track composed by Yasunori Mitsuda for the game Chrono Trigger. It is the final boss theme, as it's name implies. It is the thirteenth track on the third disk from the original soundtrack.
This theme is very different from traditional final battle, including sound that moves from one speaker to the other and Lavos's screams including in the song. This was very much a pioneer move at the time when Chrono Trigger came out.