Spitball caterpillar

I really don't know what this is, but he fell out of the tree and onto my knee. He felt like an ant, so I flicked him off before I looked. I thought it was just a piece of lint or tree fungi, then it moved! He really was the size of a spitball. He has two tiny green feelers and a tiny nose. If you look underneath all that fuzz there are several little feet like a caterpillar.