Original soundtrack composed by: Danny Pelfrey and Rick Rhodes
This track actually plays right at the beginning of the game as you meet some creepy, giant spider with a raspy voice (apparently, it's called the T'Urthrax Mata). As mentioned in this GameFAQ, the T'Urthrax Mata is
A hideous, giant black widow spirit with a skull face
and skeleton hands, the T'Urthrax Mata is the final boss
and a master of time and space.
The track definitely sounds menacing and creepy enough, as you'd expect for a giant, evil spider. One of my favourite parts of the track occurs at 0:33 so be sure to check it out :).
[ VIDEO: Choicest VGM - VGM #290 - Entomorph - Track 6 (The T'Urthrax Mata) ]