I concur with Ebony, definitely a Gray Treefrog. I'm not which of the two versions, the Eastern or the Cope's (or both) are in your area, and they look identical. Kurt and John have a great care article where you can learn more about them:

FrogForum - Gray Tree Frog Care

Funny you should mention it being like a toad, I just read last week that they are sometimes referred to as "Tree Toads". I guess it's the bumpy skin they sometimes have.