Shrooms (2007)

3 couples go to Ireland woods to collect magic mushrooms and trip out. On their way they meet some strange inhabitants of the woods and it doesn't take long until a creepy story is being told at the campfire which might be more than just a story. So strange things happen, people start disappearing, silhouettes move through the woods and the creepy story starts to melt into reality. The horror kicks in along with the effect of the mushrooms.