what's growing on the tree?

This i did for my 3D design class in the spring. Out of all the projects i did for that class i thought this was my most successful one because of this ambiguitiy feeling of this color like moss/thing growing on a tree. Originally, it wasn't suppose to be on the tree; it was a sculpture. Apparently, it didn't work well like that and it couldn't stand up. So, it worked well with the tree.