Sera are a highly nutritous Bird type creature, the only natural animals capable of living on Repmundo. They feed most of the Auctors there.
They resemble birds, however are closely related to amphibians. They can fly, and they also have special lungs that can filter out the toxic air extremely well. They were heavily modified after Auctors needed a food source on Repmundo to be highly nutrisous and feed on waste, although they must consume massive amounts. Since there are only the auctors they reproduced like mad and are almost considered pests.