Planet Zoness was originally a beautiful water planet similar to its twin planet, Aquas. It was famous for its resorts and was where Peppy Hare had taken his wife, Vivian, for their honeymoon. However, Andross' forces would invade and pollute its waters with their bioweapons, mutating the local wildlife to become larger and violent.

Early footage of Star Fox 64 circa 1996 actually show Zoness in its pure, unpolluted state, which seems to indicate that making it polluted was decided on later in development. There's actually appears to be dialogue remnants of this cleaner version in the developer's dub:


When finishing the stage:


But in the final polluted version, this exchange in the JP version goes: