European tree frog
The pupils of this frog's eyes go side to side and open up and down.  It has discs on the toes of all four feet for climbing.  This frog can be green or gray or brown or even near black depending on where it lives.  Its belly is white or yellow.  There is a dark stripe down each side of its body with white on the edges of the stripe.  Adult male frogs have a dark-colored vocal sac on their throats and females do not.