[@rush99999] Oh, good question! So part of what the Old World left behind are these colossal skeletons of all different shapes and sizes sticking out of the ground (No, not dinosaurs). Some theorise that these were left by some kind of animal that had clay for bones. They can range from towering ribcage looking things that tower hundreds of meters high, to fossilised fan like bone structures barely larger than a fingernail.

As for the here and now in the world, there are rumors and sightings of 8 foot monsters with smooth, cracked skin and hollow faces that roam forests, and small dogs with chicken heads and long, spindly limbs. There are other reports, too, but they're less common. The sources for these rumors are credible.

Regular world animals all exist, just for ease of writing.