Golgari Swarm

There are two Guilds on Ravnica that comprise the lower classes of society: Gruul, who are basically the multiverse's largest Anarchist Bike Gang, and the Golgari Swarm, which are what would happen if you kicked all of the Underdark races in DnD out onto the street, then forced them to work either as fast food servers or garbage men. That's right: there's Soy-lent Green in Ravnica, and it's more than just people.