Nigon is the second underground race.

If it's trolls, then only cave trolls, like in Tolkien's works. Big ones (just like in the movie). Then, the upgrade could be one type of troll in armor, with a helmet, and another with a gnawed bone. Overall, it would be cool. And hippos have nothing to do in caves! They love air, and barbarians too... until they get hungry. And it's not good to use them to fill a hole in the castle!

The trolls will look like ettins... they also wear armor, and another type has a stalagmite... so it's better to make them monsters)... the barbarians lived with them in caves, and everything was fine)... and in Heroes 5, it doesn't really matter, cave or dungeon, because it's a different world here... you can come up with everything from scratch)... they came up with the Dark faction, so we can "have some fun" too.