Tint portions of fondant skin tones as desired. Tint fondant various colors for hair and clothing.
Roll skin tone fondant into logs of various sizes for body torso, arms and legs; attach logs, bending as desired, to each other using fondant adhesive. Add fingers, toes, and other details using knife and gum paste/fondant tools. Roll round balls of skin tone fondant for heads; attach with fondant adhesive. Let dry. Cut out and attach fondant hair and clothing details. Add edible marker dot eyes, outline mouth and nose.
Place ice cream cones on waxed paper. Pipe green royal icing tip 16 pull-out star boughs, starting at the bottom of each cone and moving up until entire cone is covered. Let dry.
On waxed paper, pipe tip 16 red dot of royal icing; arrange pretzel stick "logs" in icing. Add yellow and red tip 16 pull-out star or tip 349 pull-out leaf "flames". Let dry.
Bake and cool single layer cake in guitar pan. Cut keys off neck area of guitar cake. Cut cake board into an oval at least 4 inches wider than the widest part of the cake; wrap with foil. Arrange cake on foil-wrapped board, angling to make space for "swimming area" near neck.
Spatula ice the cake smooth: brown buttercream icing on guitar neck "dock", green buttercream icing on guitar base "land". Pipe tip 45 brown buttercream boards and corner poles on dock. Add tip 8 gray buttercream ball rocks and tip 233 green grass around base of cake. Combine piping gel and royal blue icing color ; spread onto board around cake.
For tents, split wafer cookies and remove icing; cut sections into 2 Â½ in. x 2 in. pieces. Place at angles on top of cake; secure top with royal icing. For taller trees, insert pretzel rod into cake; pipe tip 16 icing rosette on top and position tree cone over pretzel. Position campers, campfire and gummy worms on and around cake. For roasting hot dog, form red-brown fondant around skewer; attach to camper with fondant adhesive, cutting skewer to fit.