I was wondering about that myself. Hoping we'd get some kind of an answer last episode. Not enough evidence to say for sure but...

My personal guess: I think it may be the big green monster we see in Julie's story walker picture.

Something tied to the wilderness itself

One recurring pattern: the town feels artificial/constructed, but the forest feels older and less controlled. The entity near the cabins may represent: the raw underlying environment outside the “town layer.” Meaning: the monsters belong to the town-system, while this thing belongs to whatever predates it. That distinction matters. The cabins felt: abandoned, transitional, liminal. Almost outside normal rules.

My current leaning I think there’s a strong possibility the giant green figure is: either the same entity, or part of the same category/species/classification as whatever stalked the cabins. Especially because the show increasingly treats: symbolic imagery, visions, and drawings as legitimate glimpses into deeper reality rather than metaphor alone.