Caution: Aliens at Work (Ghosts of Fear Street #32) by R.L. Stine - Vintage Paperback

Matt finds an amazing toolbox in the Fear Street Woods. When he opens it up, the tools are like none he's ever seen.

One lets him read people's minds. Another lets him freeze people in place. A third makes him grow an extra arm!

But then the owner of the toolbox comes looking for Matt. He's a big, ugly alien -- with big, ugly plans for the toolbox. And he'll do anything to get it back!