Toxic worlds are characterized by a seemingly endless rain of toxic gunk, a muddy-looking surface that is occasionally covered by a bright film of some unknown substance, and a serious infestation of various mushrooms, fungi and highly poisonous and bizarre-looking plants. When viewed from space, the planet looks muddy and has rivers of toxic ooze flowing through. The resources Ammonia, Fungal Mould and Nitrogen can be found here.

Note that Hazard protection is always on due to high amounts of toxic substances. Toxic Protection upgrades are recommended, especially on extreme worlds.

Toxic storms can occur, draining hazard protection up to three times faster than normal.

Water can be found on some toxic biomes.

Biome Subtype - Infested
The Infested subtype can overlay the normal planetary biome types, creating twisted, infected flora not seen on other planets of the same variants.

They come in six different planetary pallets with each seemingly having its own main flora type for each planetary variant. Whispering Eggs dot the landscape and Biological Horrors appear with them when broken, similar to Dead worlds.

Infested planets also display chromatic aberration filters as well as glitch music, similar to Mega Exotic and Exotic worlds.