Can you see me? Oh, hi! Such camouflage.
The NYPL PD picture I built this on names it a tree toad. Not three-toed. Its scientific name is Hyla versicolor (Wikipedia):
As the scientific name implies, gray tree frogs are variable in color owing to their ability to camouflage themselves from gray to green, depending on the substrate where they are sitting. The degree of mottling varies. They can change from nearly black to nearly white. They change color at a slower rate than a chameleon. Dead gray tree frogs and ones in unnatural surroundings are predominantly gray. The female does not croak and has a white throat; however, the male does croak and has a black/gray throat. The female is usually larger than the male.
A deserving poster-child!
And just look at this pretty fringed-, egg-nomming mouth of the tadpole of a newly-discovered tree-hole breeding frog from India: