While Candy and Tuffy escorted Ray to a section of the swamp, Ray asked them several questions about this so-called Mud Crab. The Mud Crab was apparently the big boss of the swamp, similar to the winged beast that stayed on top of the mountain, only the Mud crab was a lot weaker.
In hunting areas, there was generally one creature that was stronger than the rest. The stronger the leader was the stronger creatures it would attract around it as well. If the leader was only an intermediate class, then that area would most likely only be filled with basic tier creatures.
This was the case of the Black forest that was near Ray's village when he was younger. The wolf Ray had slain was also the boss of the forest, which was why the forest was filled with only basic tier creatures.
