What is this?

Does anyone know what this creature is?  It attacked Bill from a tree today, I've never seen anything like it.  It was about 2" long and 1/2" wide, and it had wings.  It released saliva or something from it's mouth, then hammered the area with it's head (mouth).  Fortunately, Bill was wearing leather gloves.

Carpe diem, Lil & Bill