Skaro in the mod was recently updated with new biomes and life. Other planets did the same. However, I noticed something: No planets appear to have bodies of water.
There are no lakes, rivers, or oceans, which is a little strange.
On Skaro, in particular, it was mentioned that there was a “Lake of Mutations” which featured such creatures as the Terrorkons (photo below).
along with these lakes and their assorted creatures, I suggest adding the Dalek submarines seen in that same comic strip. Submarines with Daleks (or even just naturally spawning Marine Daleks) would be great inhabitants for the lake.
As for additional bodies of water, I suggest toxic waste fill most of them, such as toxic rivers and oceans.