I guess it's too late for Halloween this year, but it will work if your camping buddies don't read this forum... Especially good if your kids like ghost stories told around the camp fire late at night! 
Go to a fishing supply store and pick up a couple of the tiny 1/2" chemical glo-lights. I find them in packs of 5 for about a dollar or two. These are the little ones made to be attached to fishing lures. Green seems to work best...
Now... wait until well after dark with no on watching, snap one of the glo-sticks, and pop it into your mouth and keep your lips closed. (Do NOT chew!) Then, at just the right moment, crack a big smile or growl, which ever suits the mood, exposing the ghoulish green light coming from your mouth!
I've done this while driving. Stopped at a traffic light and someone pulls up next to you. Just turn and smile.
Have fun!
Stitchawl
Go to a fishing supply store and pick up a couple of the tiny 1/2" chemical glo-lights. I find them in packs of 5 for about a dollar or two. These are the little ones made to be attached to fishing lures. Green seems to work best...
Now... wait until well after dark with no on watching, snap one of the glo-sticks, and pop it into your mouth and keep your lips closed. (Do NOT chew!) Then, at just the right moment, crack a big smile or growl, which ever suits the mood, exposing the ghoulish green light coming from your mouth!
I've done this while driving. Stopped at a traffic light and someone pulls up next to you. Just turn and smile.
Stitchawl