Nigon is the second underground race.

well... basically yes... hydras have many heads)) but they are more animals than humanoids)) maybe they have little brains and so on) and that's why they stick together from one castle)) or they have one main head that is responsible for everything) and the rest just bite)) who knows.... but Ettins have two and both are working))))
as for the undead, yes... it's awesome))

P.S. we'll pay and they'll make our castle :D)))))