From Back Cover:
There's something different about Joey and Nate's new teacher. He wears brown leather suits, his eyes bulge out, and his tongue is long and slimy. But all the kids like Mr. Batrachian anyway- all the kids except Joey and Nate. Joey and Nate know the truth about Mr. Batrachian. They know that he's mean. They know that he's creepy. And they know that sixth-graders are his favorite snack.