We had some similar in our other house, the neighbours hated them but that was okay as we didn't like the neighbours.
I once had a farting gnome that 'went off' if you walked past and activated a sensor. It was hidden in a bush by the front door and was ceaselessly hilarious. Got stolen though, natch.
It was a tiny shop in folkestone, years ago sadly. Bet they're online though..every home should have one.