The carnival goers
The Carnival Goers were really one of the first species to exist in this world. Goers would wander aimlessly through vast spaces of empty tents and piles of debris. Goers seem to be some form of lost soul, with no discernable life outside of visiting the circus. Their clothing indicates they all come from different regions/time periods, yet they seem to socialize effectively with one another, with little to no violence amongst themselves.
Having an exposed skull for a face is fairly common, and Carnival Goers sport a wide variety of skull shapes and sizes. Their clothing helps solidify some form of personality the longer each Goer has been at the circus, specifically what they carry on themselves. The three Goers pictured above are suspected to have been around longer than most, and are more recognizable than newcomers, who are often barely clothed.
For reasons that are unknown, carnival goers are very rarely seen during the day. Perhaps they seem to know that the circus is not open during the daylight, or perhaps they are closer to a ghost than we might think.
Carnival Goers are also more likely to be lured into The Forest. They are easy to please creatures, and can be lured into the dangerous part of the trees with simple tricks.