The reason that there are recommendations against Spanish Moss (Tillandsia usneoides) is because there are at least two documented cases of problems with it. These were reported by Dr. Kevin Wright in the old ADG (if you want to read them). In one the frog swallowed a pieces and it lacerated the internal organs on it's way through the digestive system and in a second case, the frog got a piece tangled around it's mid-body which then lacerated it's way into the frog.
I'm with Josh on the lichen.
I'm with Josh on the lichen.