The Kingdom of Rats

Official illustration by Clément de Ruyter
The Rats were already here in the humans' time, and they learned a great deal by watching them. Since the big-bare-butts vanished, they maintain as best they can what was left behind: neon signs, machinery, tunnels. They see the humans as vanished demigods, and some pray every evening for their return.
Their underground network, the GIN (Great Interraccoon Network), runs invisible beneath the whole world, all the way into the sewers of Cat Tree City. A Rat will lead Kittens from one place to another through these tunnels and refurbished old metro trains, provided they get a service or a small treasure in return. The trip avoids the Yardogs and links, for example, Crimsonfief to Cat Tree City, Huggle to Corktown or to Bigwheel.
Depending on the route, travelers move in a boat made of tin cans, on a small mechanical wagon that squeaks along the rusty rails of an old metro, on the back of Chuckie, a tamed giant centipede, in a cobbled-together submarine, or through a supernatural toilet flush that teleports travelers to whatever destination they have in mind.
Notable characters
Beep and Squeek, two sewer archaeologists, are recognizable by their head torches and big backpacks. These brilliant engineers build almost anything from what they gather and know the tunnels better than anyone.
Louis the Learned, perched on a broken old television set, stages plays performed by animals inside the set. They tell of ancient times, of the humans, of catastrophes, but also of love and adventure, and all the animals nearby come to watch.