The Beast from the East (Goosebumps #43)

Ginger Wald and her identical twin brothers, Nat and Pat, are lost in the woods. No problem. After all, Ginger did go to that stupid nature camp. Still, there's something odd about this part of the woods. The grass is yellow. The bushes are purple. And the trees are like skyscrapers. Then Ginger and her brothers meet the beasts. They're big blue furry creatures. And they want to play a game. But in this game, the winners get to live. The losers get eaten...