The Magical Pony #4: The School Camping Trip

Vigga is going on a school camping trip in Jutland.
Vigga brings Luna, but keeps her hidden in a bag, because she doesn’t want the other kids to see her.
One night, Vigga and Luna go for a ride in the woods, where they meet Vigga’s classmate, Anker.
What’s he doing in the woods at this late hour? And what’s that scary sound?