Hi, really enjoying the mod so far !
I attempted to follow the instructions on how to add new ennemies, but it seem i can't follow properly a template, or maybe i missed something, i couldn't get the toxic biters to spawn in the game at night in test settings. It was quite frustrating because it looked in the code that they are defined very similarly to the armored biters or the vanilla one :
https://mods.factorio.com/mod/Toxic_biters
https://mods.factorio.com/mod/Explosive_biters
There are also cold biters that i've used https://mods.factorio.com/mod/Cold_biters but i'm playing on a desert map. I found those 3 look like the armored biters in their design , similarly close to vanilla biters in their look with a unique distinctive feature that has unique gameplay implication for each, hence the suggestion. I think they would be a nice addition, and i could use them in my game, and read the correction to my lua attempt x).