Amphibians with huge claws
Riggens are a species without a homeworld, their birthplace lost in the mists of time. Physically, they resemble large frogs, although they have a tougher outer skin and large claws more reminiscent of a crab. They are as comfortable out of water as they are in it, only needing large bodies of water for breeding purposes.
Huge clans everywhere
Massively adaptable, Riggen are completely at home in the human-dominated cluster, and most cities have a thriving Riggen district. Non-riggen landlords view them as near ideal tenants who maintain (and improve) properties without being asked, and always pay the rent on time.
Using their claws for heavy lifting, and their dextrous smaller limbs for detailed work, Riggen are renowned as the best mechanics, surgeons, and technical experts in the cluster. However, they do not deal well with estimates and guesswork – while they understand the idea, and even the necessity for it, it seems to make them uncomfortable on an instinctual level.