"The damage is way more severe than we thought. There’s extensive flooding on top of the kind of vandalism and general destruction you find in abandoned places like this. The moisture in the air has brought about an infestation of a strange, pale root that has wormed its way through the walls and floors of the building. I’m unsure of its toxicity, I’ve taken a sample to look at back at home. We are leaving before nightfall. Jeremy thinks he saw someone else here, and I keep... hearing something like scratching at the drywall. The skin on my hand is starting to feel raw and irritated where I touched the root, and I want to get it checked out as soon as possible."
The Root Figures are a species of monster created by Trevor Henderson.
The Root Figures appear to be large plant-like organisms with a vaguely humanoid shape, complete with a "head" on top. Their heads appear to have shallow divots just barely resembling a face, though whether they have any actual function is unclear. Sprouting from their limbs are many thin branches which, though fragile-looking, are apparently strong enough to allow them to stand upright.
While the Root Figures don't appear to be outwardly hostile, the image description reveals the potential danger they pose. Originally discovered in an abandoned building, they were identified not as a creature, but as an infestation of an unknown species of pale roots growing throughout the facility. As the caption implies, direct skin contact with the roots causes irritation and inflammation, indicating that these roots are poisonous in some way similar to Poison Oak and similar plants.
The Root Figures themselves are never directly referenced- it's possible the caption predates their discovery. It's also implied that the Root Figures were once human, and that the author's skin irritation is merely the first symptom of their inevitable transformation.