Rhek

The rhek are a race of rhino-men who help maintain order in the plane of the Peaceable Kingdoms of Arcadia. They're one of the races that make up the Harmonium, a militant sect that enforces lawful goodness through violence. Seems a bit of a contradiction, but that's what paladins do, really. The Harmonium seeks to create a dictatorship of goodness, where those who adhere to their ideals are guaranteed peaceful, prosperous lives. It's supposed to be of those philosophical questions about order and goodness at the cost of freedom. Can we truly call ourselves good if we don't have the option to be evil? At what point does governing and eforcing cross over into tyranny?

Honestly, the idea of the Harmonium (who also served as the police force in the inter-dimensional city of Sigil) is a bit more interesting that the rhek themselves. Though you can see how they would make good enforcers of the law, since they have abilities that let them detect and smite chaotic creatures. They also seem to share one trait with the krogan from the Mass Effect games: redundant organs. This translates into rhek basically continuing to fight until they are stone dead.