Mystery in the Night Woods by John Peterson, 2nd Scholastic paperback printing, TW1421, March 1970, 80 pages. Illustrated by Cindy Szekeres.
DESCRIPTION: “Weasel stuck his head out of the window and whistled. A dark cloud came out and floated past him.
Bat looked on from his hiding place. He could hardly believe what he had seen. What was the dark cloud? Where did it go? Bat was sure of only one thing- Weasel was up to something crooked again.” (from the back cover)