Spores are stationary alien organisms seen in the alien world Xen. They consist of a spherical, beige body with a concave tip, connected to a surface by five dark brown root-like legs. Their body appears to be bulging in a manner similar to breathing. They appear in groups and in various sizes, posing no threat to any nearby creatures.
Behind the scenes
Comments in the source code indicate some planned but unimplemented features. The three sizes of spores, small, normal, and large, are set to use different skins, but in the final game, they all only have one appearance. When damaged, spores were to release smoke which would cause damage. It's also suggested that spores could react in some manner to the player's close proximity, but this behavior isn't specified.
The Dreamcast version features some visual changes along with additional animated features. The tip's appearance is more mouth-like and opens and closes during its breathing motions. Its legs also bend as it pulsates.
Spore behind Bullsquids drinking from a Healing Pool on Xen.