I did this exact project 3 years ago and it works great. When I bought the pickets at Lowes, the guy helping me pick them off the pile thought it was curious that I didn't mind getting the ones that aren't perfect. A little mold and discoloration makes it all the better. The first year, I stored it outside and there was some warping of the boards so the lid didn't quite fit the next year. I cut off the end of the one that was curved inward and holding the lid up and used that spot for a skeleton hand to stick out.
Mine has a wiper motor in it with push rod to bump the lid up and down for motion. The lid can get heavy if it gets rained on, and the motor burned out this year from the effort. I'm going to add some springs to help with the weight next year.
It's funny; you just don't see it yet.