Subterranean Savannahs are a relatively flat biome that are very much reminiscent of Overworld savannahs, with the notable exception of being in the Erebus and hence full of insects rather than Creepers.
They consists of a large area of grass, often surrounded by massive walls of Umberstone, and a lot of shelves and overhanging plateaus.
There is a moderate population of Acacia Trees in these biomes, with Baobab and Giant Baobab Trees rarely spawning as well as occasional pockets of Asper Trees. Amber deposits and Overworld Stone boulders (featuring Silverfish Monster Egg Stone and any Overworld mod-based ores set to spawn, such as Tin) can be found as well. There are no other plants in this biome besides the ground-based and Tall variants of Grass. Hollow Acacia Logs dot the landscape.
Many varieties of mob spawn in Subterranean Savannahs:
- Beetle Larvae
- Grasshoppers (and, by extension, Locusts)
- Wasps (and, by extension, Hornets of Despair)
- Chameleon Ticks
- Very, VERY rarely, Bamboo stalks can spawn in a Subterranean Savannah.