Planarian.
My best guess is that this is a juvenile Carphophis amoenus. I found her just off of Skyline Drive at about in Virginia at about 2400'
Happy Halloween! This character was oozing about in the moss covering the side of a tree so I grabbed this close-up of his lovely color scheme. If it's a Halloween snake, the genus is Pliocercus. Fairly common at La Selva Bio Station.