R.L. Stine 
Just Beyond: The Horror at Happy Landings [PDF ebook] 

Family camping trips are supposed to be fun, but for Parker, Annie, and the Walden family, they’re an absolute nightmare!After a creepy, unidentified bird attacks their mom in the forest, Parker and Annie find themselves face to face with two strange creatures that suddenly enter the kids’ brains and take control of their bodies. Can Parker and Annie break loose of this horrific control and convince their family of what’s happening, or will the creatures take over their lives for good?