Combine two parts plain Greek yogurt with one part creamy peanut butter in a bowl and mix well. Drop by heaping spoonfuls onto a sheet of aluminum foil and stick in the freezer for a few hours. Then you can take the blobs of frozen yogurt off the foil and store them in a sealed container with a lid. Serve one at a time when your doggie needs a cool treat. You can also let your doggie lick the bowl - Isaac loves that!